Monday, 17 July 2017

Sentence Correction




Directions (1-15): In the following sentence correction questions, a part of the sentence is in bold. From the given options find the grammatically correct option.

Q1. The Glass House Mountains in Queensland, Australia, were sighted in 1770 by the English navigator Captain James Cook, by whom they were named supposedly because its sheer wet rocks glistened like glass.
(a) by whom they were named supposedly because its
(b) by whom they were named supposedly and their
(c) naming them supposedly since their
(d) who so named them supposedly because their
(e) who so named it since supposedly their

Q2. Although a surge in retail sales have raised hopes that there is a recovery finally under way, many economists say that without a large amount of spending the recovery might not last.
(a) have raised hopes that there is a recovery finally
(b) raised hopes for there being a recovery finally
(c) had raised hopes for a recovery finally being
(d) has raised hopes that a recovery is finally
(e) raised hopes for a recovery finally

Q3. Although various eighteenth-and nineteenth-century American poets had professed an interest in Native American poetry and had pretended to imitate Native American forms in their own works, until almost 1900, scholars and critics did not begin seriously to study traditional Native American poetry in native languages.
(a) until almost 1900, scholars and critics did not begin seriously to study
(b) until almost 1900 scholars and critics had not begun seriously studying
(c) not until almost 1900 were scholars and critics to begin seriously to study
(d) it was not almost until 1900 when scholars and critics began to seriously study
(e) it was not until almost 1900 that scholars and critics seriously began studying

Q4. Of all the vast tides of migration that have swept through history, maybe none is more concentrated as the wave that brought 12 million immigrants onto American shores in little more than three decades.
(a) maybe none is more concentrated as
(b) it may be that none is more concentrated as
(c) perhaps it is none that is more concentrated than
(d) maybe it is none that was more concentrated than
(e) perhaps none was more concentrated than

Q5. Diabetes, together with its serious complications, ranks as the nation’s third leading cause of death, surpassed only by heart disease and cancer.
(a) ranks as the nation’s third leading cause of death, surpassed only
(b) ranks as the nation’s third leading cause of death, only surpassed
(c) has the rank of the nation’s third leading cause of death, only surpassed
(d) are the nation’s third leading causes of death, surpassed only
(e) have been ranked as the nation’s third leading causes of death, only surpassed

Q6. In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were closed to visitors for cleaning and repair due to moisture exhaled by tourists, which raised its humidity to such levels so that salt from the stone was crystallizing and fungus was growing on the walls.
(a) due to moisture exhaled by tourists, which raised its humidity to such levels so that salt from the stone was crystallizing
(b) due to moisture that tourists had exhaled, thereby raising its humidity to such levels that salt from the stone would crystallize
(c) because tourists were exhaling moisture, which had raised the humidity within them to levels such that salt from the stone would crystallize
(d) because of moisture that was exhaled by tourists raising the humidity within them to levels so high as to make the salt from the stone crystallize
(e) because moisture exhaled by tourists had raised the humidity within them to such levels that salt from the stone was crystallizing

Q7. As its sales of computer products have surpassed those of measuring instruments, the company has become increasingly willing to compete for the mass market sales they would in the past have conceded to rivals.
(a) they would in the past have conceded to rivals
(b) they would have conceded previously to their rivals
(c) that in the past would have been conceded previously to rivals
(d) it previously would have conceded to rivals in the past
(e) it would in the past have conceded to rivals

Q8. The widely accepted big bang theory holds that the universe began in an explosive instant ten to twenty billion years ago and has been expanding ever since.
(a) that the universe began in an explosive instant ten to twenty billion years ago and has been expanding
(b) that the universe had begun in an explosive instant ten to twenty billion years ago and had been expanding
(c) that the beginning of the universe was an explosive instant ten to twenty billion years ago that has expanded
(d) the beginning of the universe to have been an explosive instant ten to twenty billion years ago that is expanding
(e) the universe to have begun in an explosive instant ten to twenty billion years ago and has been expanding

Q9. Like the idolization accorded the Brontes and Brownings, James Joyce and Virginia Woolf are often subjected to the kind of veneration that blurs the distinction between the artist and the human being.
(a) Like the idolization accorded the Brontes and Brownings,
(b) As the Brontes’ and Brownings’ idolization,
(c) Like that accorded to the Brontes and Brownings,
(d) As it is of the Brontes and Brownings,
(e) Like the Brontes and Brownings,

Q10. Carnivorous mammals can endure what would otherwise be lethal levels of body heat because they have a heat-exchange network which kept the brain from getting too hot.
(a) which kept
(b) that keeps
(c) which has kept
(d) that has been keeping
(e) having kept

Q11. There are several ways to build solid walls using just mud or clay, but the most extensively used method has been the forming of bricks out of mud or clay, and, after some preliminary air drying or sun drying, they are laid in the wall in mud mortar.
(a) the forming of bricks out of mud or clay, and, after some preliminary air drying or sun drying, they are laid
(b) forming the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them
(c) having bricks formed from mud or clay, and after some preliminary air drying or sun drying, they were laid
(d) to form the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them
(e) that bricks were formed from mud or clay, which, after some preliminary air drying or sun drying, were laid

Q12. Rising inventories, when unaccompanied correspondingly by increases in sales, can lead to production cutbacks that would hamper economic growth.
(a) when unaccompanied correspondingly by increases in sales, can lead
(b) when not accompanied by corresponding increases in sales, possibly leads
(c) when they were unaccompanied by corresponding sales increases, can lead
(d) if not accompanied by correspondingly increased sales, possibly leads
(e) if not accompanied by corresponding increases in sales, can lead

Q13. A surge in new home sales and a drop in weekly unemployment claims suggest that the economy might not be as weak as some analysts previously thought.
(a) claims suggest that the economy might not be as weak as some analysts previously thought
(b) claims suggests that the economy might not be so weak as some analysts have previously thought
(c) claims suggest that the economy might not be as weak as have been previously thought by some analysts
(d) claims, suggesting about the economy that it might not be so weak as previously thought by some analysts
(e) claims, suggesting the economy might not be as weak as previously thought to be by some analysts

Q14. Sunspots, vortices of gas associated with strong electromagnetic activity, are visible as dark spots on the surface of the Sun but have never been sighted on the Sun’s poles or equator.
(a) are visible as dark spots on the surface of the Sun but have never been sighted on
(b) are visible as dark spots that never have been sighted on the surface of the Sun
(c) appear on the surface of the Sun as dark spots although never sighted at
(d) appear as dark spots on the surface of the Sun, although never having been sighted at
(e) appear as dark spots on the Sun’s surface, which have never been sighted on

Q15. Warning that computers in the United States are not secure, the National Academy of Sciences has urged the nation to revamp computer security procedures, institute new emergency response teams, creating a special nongovernment organization to take charge of computer security planning.
(a) creating a special nongovernment organization to take
(b) creating a special nongovernment organization that takes
(c) creating a special nongovernment organization for taking
(d) and create a special nongovernment organization for taking
(e) and create a special nongovernment organization to take


Solutions
S1. Ans.(d)
Sol. Agreement; Rhetorical construction
To avoid a wordy and confusing series of passive clauses, the relative clause explaining what James Cook did should be an active-voice construction (who so named rather than by whom they were named). The possessive pronoun referring to the Glass House Mountains should be plural (their rather than its), to agree with the plural antecedent.
Hence, D is Correct. This concise sentence uses active-voice construction in the relative clause and maintains agreement between the pronoun their and its antecedent.

S2. Ans.(d)
Sol. Agreement; Rhetorical construction
The subject of the first clause, the singular noun surge, must take the singular verb has raised rather than the plural “have raised”. It is superfluous and pointless to say that people hope both that there is a recovery and that such a recovery is underway. In this context, ‘there is’ adds nothing and can be omitted to create a more concise sentence.
Hence, (d) is Correct. In this sentence, the subject and verb agree, and the verb is in the appropriate tense; “a recovery is finally” is clear and concise.

S3. Ans.(e)
Sol. Verb form; Rhetorical construction
The past-perfect verbs had professed and had pretended designate a time (eighteenth and nineteenth century) earlier than simple past tense, so the second clause, explaining what happened around 1900, must use the past tense. The placement of the phrase until almost 1900 at the beginning of the second clause is confusing. Does it refer back to the first verb or forward to the next verb?
Hence, (e) Correct. The phrase “not until almost 1900” is properly placed, and the verb in the main clause is in the simple past tense.

S4. Ans.(e)
Sol. Idiom; Verb form
This sentence depends on the comparative structure x is more than y. Here, an idiomatically incorrect construction x (none) is more as y (the wave) is used. In addition, the second part of the sentence uses the past tense verb brought, indicating that the event is over. The verb used in the comparative construction must also be past tense, x (none) was more concentrated than y (the wave). Maybe and perhaps are interchangeable; perhaps is slightly more formal.
Hence, (e) is Correct. The correct comparative construction is used in this sentence; the verb is past tense.

S5. Ans.(a)
Sol. Agreement; Logical predication
This sentence correctly matches the singular verb, ranks, with the singular subject, diabetes, and uses the present tense to indicate a current situation. The phrase following diabetes is set off by a pair of commas, indicating that it is descriptive information that may be dropped from the sentence; it is not a part of the subject. Only is placed with precision next to the group of words it actually limits, by heart disease and cancer. Placed before surpassed, only would more ambiguously limit surpassed.
Hence, (a) Correct. In the original sentence, the subject and verb agree, and the proper tense is used; only is correctly placed next to the phrase it limits.

S6. Ans.(e)
Sol. Agreement; Parallelism
The plural subject chambers require plural pronouns. The sentence explains a causal sequence: visitors’ breadth introduced moisture that caused salt to crystallize, which caused the chambers to be closed for cleaning and repair. The phrase due to makes this causal sequence somewhat ambiguous, seeming to suggest that the repairs were due to humidity from visitors’ breath.
(e) Correct. The causal sentence is clear, and them clearly refers to chambers.

S7. Ans.(e)
Sol. Agreement; Rhetorical construction
When a number of words intervene between a pronoun and its referent, an error such as the one in this sentence is easy to make. The subject of the main clause is the singular noun company, so the pronoun referring to the company must also be singular. Even if the company might be thought of as referring to the members of a business, the singular verb (has become increasingly willing) establishes that the noun is singular in this sentence.
Hence, (e) Correct. In this concise sentence, the singular pronoun it agrees with the singular referent the company.

S8. Ans.(a)
Sol. Logical predication; Verb form
The sentence describes the central tenet of a theory about how the universe began. The focus of the second clause should be consistently on the subject the universe, and all verbs in the clause beginning with that must describe what the universe did at the initial explosive moment.
Hence , (a) is Correct. Both verbs in the second clause correctly take universe as their subject.

S9. Ans.(e)
Sol. Logical predication
This sentence intends to compare nineteenth-and twentieth-century writers. Instead the comparison becomes ambiguous and illogical. Like must be used to compare similar elements: Joyce and Woolf are like the Brontes and the Brownings; they are not like the idolization.
(e) Correct. In this sentence, like introduces a clear and concise comparison that correctly links the nineteenth-and twentieth-century writers.

S10. Ans.(b)
Sol. Verb form; Rhetorical construction
The use of the past tense (kept) is incorrect because a current situation is discussed; the present tense (keeps) is consistent with the other verbs in the sentence. In (A) and (C), which introduces a restrictive clause. Some writers follow the convention that which can only be used for nonrestrictive clauses, but insistence on this rule is controversial, and both (A) and (C) can be rejected on other grounds.
Hence, (b) is Correct. The verb keeps indicates a current situation and is consistent with the other verbs in the sentence. The sentence is clear and concise.

S11. Ans.(d)
Sol. Parallelism; Verb form
The purpose of the sentence is to describe the historically most popular method of building walls. The first clause announces this topic and the second clause describes the particular method. The clearest, most efficient way to accomplish these two pieces of business is to use a parallel structure. The ways to build in the first clause is narrowed to the single way to form and to lay in the second clause. These is no need to alternate the verb phrases between active and passive voice or to shift tenses.
Hence, (d) is Correct. The phrases to form and to lay in the second clause are parallel to “to build” in the first clause.

S12. Ans.(e)
Sol. Diction; Agreement
The modifying phrase when… sales is needlessly difficult to understand. The adverb correspondingly is incorrectly and ambiguously used; using the adjective corresponding to modify increases in sales makes the intended meaning clearer. Unaccompanied is not wrong but not accompanied more effectively expresses the intended negation.
(e) Correct. Not accompanied emphasizes the negative and is preferable to unaccompanied in this usage; corresponding modifies increases in sales; the modifier is clear and comprehensible, and there is no subject-verb agreement problem.

S13. Ans.(a)
Sol. Agreement; Grammatical construction
The plural subject of this sentence (surge and drop) requires a plural verb, suggest. The object of this verb, the clause beginning with that, should be presented in as clear and direct a manner as possible.
(a) Correct. The plural subject is matched with a plural verb.

S14. Ans.(a)
Sol. Logical predication; Parallelism
The correct parallel structure in the original sentence emphasizes the contrast between where sunspots are found (are visible… Sun) and where they are not (have never been sighted… equator). Sunspots is the subject of the sentence; are is the verb of the first part of the contrast, and have been sighted is the verb of the second. (The adjective visible is a complement and is parallel to the past participle sighted.) Both parts of the sentence conclude with phrases indicating location. The contrast itself is indicated by the conjunction but.
(a) Correct. This sentence clearly and correctly draws a contrast between where sunspots are found and where they are not.

S15. Ans.(e)
Sol. Parallelism; Grammatical construction
This sentence contains a list of three elements, all of which should be parallel. The last element should be preceded by the conjunction and. In this sentence, the last element must be made parallel to previous two: to (1) revamp computer security procedures, (2) institute new emergency response teams, and (3) create a special nongovernment organization to take charge of computer security planning. Omitting and causes the reader to anticipate still another element in the series when there is none. Using the participle creating not only violates parallelism but also causes misreading since the participial phrase could modify the first part of the sentence. To does not need to be repeated with institute and create because it is understood.
(e) Correct. The three elements in the series are parallel in this sentence, and the last is preceded by ‘and’.

Sunday, 16 July 2017

Daily GK Update 16th July 2017



i. The government has launched a GST training programme to skill around two lakh youths in six months to handle tax compliance issues like invoice making. The people would be trained under the Pradhan Mantri Kaushal Vikas Yojana (PMKVY).

ii. The new training course would cater to the need of GST trained professionals to help businesses in areas such as registration and calculation of tax liability under the new tax regime.

Important Takeaways from the above News:
  • Rajiv Pratap Rudy is Union Minister of State for Skill Development and Entrepreneurship (Independent Charge).
  • Pradhan Mantri Kaushal Vikas Yojana (PMKVY) is the flagship scheme of the Ministry of Skill Development & Entrepreneurship (MSDE).
  • GST is a single tax on the supply of goods and services, right from the manufacturer to the consumer.

i. UNICEF appointed Indian- origin Canadian YouTube star Lilly Singh as its newest Global Goodwill Ambassador at a special event in New Delhi.

ii. Lilly was in the capital to support UNICEF’s Youth4Change initiative, a programme for youth that brings them together to support their peers and communities in taking action on issues such as health, hygiene, child labour and gender equality.

Important Takeaways from the above News:
  • UNICEF stands for United Nations International Children's Emergency Fund.
  • The Head office of UNICEF is in New York, US.

i. Senior advocate K K Venugopal’s name has been cleared for appointment as the Attorney General for India following the decision of Mukul Rohatgi to step down as the top law officer.

ii. The Law Ministry had recently referred the file relating to the appointment of Venugopal as the Attorney General.

i. The 18th edition of the International Indian Film Academy Awards was held in New York. Sonam Kapoor’s film Neerja won the best film award. Actor Shahid Kapoor earned the Best Actor award for his role in Udta Punjab, while Alia Bhatt won the Best Actor (Female) award for the same film.

ii. Here’s the complete list of the IIFA 2017 winners:
  • Best Film- Neerja
  • Best Director- AnirudhRoy Chaudhary for Pink
  • Best Actor (Male)- Shahid Kapoor for Udta Punjab
  • Best Actor (Female)- Alia Bhatt for Udta Punjab
  • Best Actor in Supporting Role (Female)- Shabana Azmi for Neerja
  • Best Actor in Supporting Role (Male)- Anupam Kher for MS Dhoni: The Untold Story
  • Best Debutant (Female): Disha Patani for M.S. Dhoni: The Untold Story
  • Best Debut (Male)- Diljit Dosanjh for Udta Punjab
  • Best Lyricist- Amitabh Bhattacharya for the song Channa Mere Ya from Ae Dil Hai Mushkil
  • Best Playback Singer (Male)- Amit Mishra for Ae Dil Hai Mushkil
  • Best Playback Singer (Female)- Kanika Kapoor for Udta Punjab and Tulsi Kumar for Airlift
  • Best Music Direction- Pritam for Ae Dil Hai Mushkil
  • Best Actor In Comic Role- Varun Dhawan for Dishoom
  • Myntra Style Icon Award- Alia Bhatt
  • IIFA Woman Of The Year- Tapsee Pannu

i. Central Railway has taken a step towards women empowerment by appointing an all-female work staff at the suburban Matunga station. Matunga station has now become the first such ladies special station.

ii. According to the official, women have been manning this station, which falls on the Central Railway, since the past two weeks. A total of 30 women staffers, including 11 booking clerks, five RPF personnel, seven ticket checkers are working under the supervision of station manager Mamta Kulkarni since last two weeks.

i. Garbine Muguruza of Spain came out with the spectacular performance as she defeated seven-time Grand Slam Champion Venus Williams in straight sets to clinch her maiden Wimbledon title.

ii. The 14th-seeded Spaniard defeated Williams 7-5, 6-0 in what eventually turned out to be a one-sided contest lasting one hour and 23 minutes on the Centre court.

Quant Quiz


Quant Quiz

Directions—(1–5) Study the following table carefully to answer the questions that follow—
The following table gives number of people in different villages and percentage of Men, Women and Children in these villages.










1. Which village has the least number of children?
(1) L 
(2) N
(3) Q 
(4) O
(5) None of these

2. What is the respective ratio of the number of women in Villages L and P together to the number of men in the same villages together?
(1) 617:664
(2) 629:691
(3) 664 : 617
(4) 691 :629
(5) None of these

3. What is the total number of women and children together in Village Q?
(1) 995
(2) 1184
(3) 1086
(4) 988
(5) None of these

4. The total number of people from Village O is approximately what per cent of the total number of people from all the Villages together ?
(1) 16 
(2) 21
(3) 11 
(4) 25
(5) 9

5. What is the total number of children from Villages M and N together ?
(1) 785
(2) 825
(3) 855
(4) 795
(5) None of these

Directions—(Q. 6–10) Study the following Pie-chart carefully to answer these questions.
The following pie-chart gives the expenditure of funds by university for various purposes.

Total expenditure is 60 lac.



















6. What is the total sum of expenditure on Research work, Purchase of overhead projectors for Ph.D. Classes and Purchase of books for Library together ?

(1) Rs. 22•6 lac
(2) Rs. 22•8 lac
(3) Rs. 23•4 lac
(4) Rs. 20•8 lac
(5) None of these

7. What is the difference between the expenditure made by university for Publication of Journals and Psychology Laboratory ?
(1) Rs. 4 lac
(2) Rs. 3 lac
(3) Rs. 4•2 lac
(4) Rs. 3•8 lac
(5) None of these

8. What is the respective ratio between the expenditure made by university on research work and purchase of books for library ?
(1) 4 : 5 
(2) 5 : 4
(3) 8 : 3 
(4) 8 : 5
(5) None of these

9. If the expenditure on purchase of overhead projectors for Ph.D. Students is decreased by 7%, what will be the expenditure on the same after the decrease ?
(1) Rs. 1,33,920
(2) Rs. 13,39,200
(3) Rs. 1,02,000
(4) Rs. 1,08,000
(5) None of these

10. Which of the following is definitely true ?
(1) Ratio between expenditure of university for the purchase of library books and expenditure on computer laboratory is 3 : 1 respectively
(2) Expenditure on medical facilities for students is Rs. 4•6 lac
(3) Difference between the expenditure on research work and medical facilities for student is Rs. 60,000
(4) All are true
(5) None of these



ANSWERS
Solutions (1-5)
Village
Total number of people
Number of men
Number of women
Number of children
L
1240
434
558
248
M
2140
963
642
535
N
1450
725
435
290
O
1680
1092
336
252
P
2060
824
824
412
Q
1990
796
995
199
Total
10560
4834
3790
1936

1. (3) According  to the table.

2. (4)
Required ratio = (558 + 824) : (434 + 824) = 691 : 629

3. (5)
Required sum = 995 + 199 = 1194.

4. (1)
Required percentage = 1680/10560 * 100 = 16%.

5. (2)
Required sum = 535 + 290 = 825


Solutions (6-10)
6. (2)
Required sum = (8 +24 + 6)% of 60 = 22.8 lac

7. (2)
Required difference = (15 – 10)% of 60 = 3 lac.

8. (5)
Required ratio = 8 : 6 = 4 : 3

9. (2) The expenditure of overhead & projector for PHD= 24% of 60lakh= 14.40lakhs.
According to the qs. 7% of 14.40 = 1.008 lakhs

The Expenditure after the decrease = 14.40 – 1.008 = 13.392 = 1339200

10. (3)
In option (1), the ratio is 1 : 3 not 3 : 1, so (1) is not true.
In option (2), the expenditure on medical facilities = 7% of 60 = 4.2 lacs, hence (2) is not true.
In option (3) the difference = (8 – 7) % of 60 lac = 60000. Hence (3) is true.

Average


Average

An average or an arithmetic mean of given data is the sum of the given observations divided by number of observations.

Important Formulae Related to Average of numbers

1. Average of first n natural number=(n+1)/2

2. Average of first n even number= (n+1)

3. Average of first n odd number= n

4. Average of consecutive number= (Firtst number+Last number)/2

5. Average of 1 to n odd numbers=  (Last odd number+1)/2

6. Average of 1 to n even numbers=  (Last even number+2)/2

7. Average of squares of first n natural numbers=[(n+1)(2n+1)]/6

8. Average of the cubes of first n natural number=[n(n+1)^2]/4

9. Average of n multiples of any number=[Number*(n+1)]/2


Concept 1 
If the average of n_1 observations is a_1; the average of n_2 observations is a_2 and so on, then
Average of all the observations=(n_1* a_1+n_2 *a_2+......)/(n_1+n_2+........)

Concept 2 
If the average of m observations is a and the average of n observations taken out of  is b, then
Average of rest of the observations=(ma-nb)/(m-n)

Example 1 : A man bought 20 cows in RS. 200000. If the average cost of 12 cows is Rs. 12500, then what will be the average cot of remaining cows?

Here m = 20 , n = 12 , a = 10000 , b = 12500 

average cost of remaining cows ( 20-8) cows = (20*10000 - 12*12500)/(20-8) =Rs  6250

Concept 3 
If the average of n students in a class is a, where average of passed students is x and average of failed students is y, then
Number of students passed=[Total Students (Total average-Average of failed students)]/(Average of passed students-Average of failed students)
=[n(a-y)]/(x-y)

Example 2: In a class, there are 75 students are their average marks in the annual examination is 35. If the average marks of passed students is 55 and average marks of failed students is 30, then find out the number of students who failed.

Here , n = 75 , a = 35 , x = 55 , y = 30 
Number of students who passed = 75(35- 30)/(55- 30) = 15
Number of students who failed  = 75- 15 = 60

Concept 4
If the average of total components in a group is a, where average of n components (1st part) is b and average of remaining components (2nd part) is c, then Number of remaining components (2nd part)=[n(a-b)]/(c-a)

Example 3 : The average salary of the entire staff in an offfice is Rs. 200 per day. The average salary of officers is Rs. 550 and that of non-officers is Rs. 120. If the number of officers is 16, then find the numbers of non-officers in the office.

Here n= 16 , a = 200 , b = 550 , c = 120 


Number of non - officer = 16(200- 550)/(120- 200) = 70 

Average Speed
Average speed is defined as total distance travelled divided by total time taken. 
Average speed=Total distance travelled/ Total time taken

Case 1
If a person covers a certain distance at a speed of A km/h and again covers the same distance at a speed of B km/h, then the average speed during the whole journey 
will be 
2AB/A+B

Case II
If a person covers three equal distances at the speed of A km/h, B km/h and C km/h respectively, then the average speed during the whole Journey will be 
3ABC/(AB+BC+CA)

Case III
If distance P is covered with speed x, distance Q is covered with speed y and distance R is covered with speed z, then for the whole journey,
Average speed=(P+Q+R+.....)/(P/x+Q/y+R/z+...)

Example 4 : A person covers 20 km distance with a speed of 5 km/h, then he covers the next 15 km with a speed of 3 km/h and the last 10 km is covered by him with a speed of 2 km/h. Find out his average speed for the whole journey. 

 Average speed  =  ( 20 +15 +10)/(20/5+15/3+10/2) = 3(3/14)

Case IV
If a person covers P part of his total distance with speed of x, Q part of total distance with speed of y and R part of total distance with speed of z,then
Average speed=1/(P/x+Q/y+R/z+......)



If you have missed the "Quant Handy Concepts and tricks on Percentages"Click here

To do the Quizzes based on "Average", click on the below links -
1. Quiz 1
2. Quiz 2
3. Quiz 3
4. Quiz 4
5. Quiz 5
6. Quiz 6