Quant Quiz-Simple Interest

Quant Quiz-Simple Interest

1.A sum of Rs. 1600 gives a simple interest of Rs. 252 in 2 years and 3 months. 

The rate of interest per annum is:?

(a)51/2%

(b) 8%

(c) 7%

(d) 6%

(e)none of these

2.A sum of Rs. 1750 is divided into two parts such that the interests on the first part at 8% simple interest per annum-

 and that on the other part of 6% simple interest per annum are equal. The interest on each part (In rupees) is ?

(a) 60

(b) 65

(c) 70

(d) 40

(e)none of these

3.Rs. 500 was invested at 12% per annum simple interest and a certain sum of money invested at 10% per annum simple interest at.

 If the sum of the interests on both the sums after 4 years is Rs. 480, the latter sum of money is? 

(a  Rs. 450

(b) Rs. 750

(c) Rs. 600

(d) Rs. 550

(e)none of these

4.A sum of money lent out at simple interest amounts of Rs. 720 after 2 years and to Rs. 1020 after a further period of 5 years. The sum is?

(a)Rs. 500

(b) Rs. 600

(c) Rs. 700

(d) Rs. 710

(e)none of these

5.In what time will Rs. 72 become Rs. 81 at 25/4% per annum simple interest? 

(a2 years 

(b) 3 years 

(c) 2 years 6 months 

(d) Can't determine

(e)None of these 

6.The simple interest on a certain sum for 8 months at 4% per annum is Rs. 129 less than the simple interest on the same sum for 15 months at 5% per annum. The sum is: 

(a) Rs. 2580

(b) Rs. 2400

(c) Rs. 2529

(d) Rs. 3600

(e)None of these 

7.A person deposited Rs. 400 for 2 years, Rs. 550 for 4 years and Rs. 1,200 for 6 years. He received the total simple interest of Rs. 1,020. 

The rate of interest per annum is ?

(a)10%

(b) 5%

(c) 15%

(d) 20%

(e)None of these 

8.A sum of money becomes 7/6 of itself in 3 years at a certain rate of simple interest. The rate per annum is?

(a) 5 5/9%

(b) 6 5/9%

(c) 18%

(d) 25%

(e)None of these 

9.At what rate per cent per annum will the simple interest on a sum of money be 2/5 of the amount in 10 years? 

(a) 4

(b) 6

(c) 52/3

(d) 62/3

(e)None of these 

10.Simple interest on a certain sum for 6 years is 9/25 of the sum. The rate of interest is ?

(a) 6%

(b) 6 1/2%

(c) 8%

(d) 8 1/2%

(e)None of these 

Answers:

1.(c)
Principal, P = Rs. 1600
T = 2 year 3 months
= (2+3/12)yrs.=(2+1/4)yrs.= 9/4 yrs.
S.I = Rs. 252
R = % rate of interest per annum
R= (100×S.I.)/(P×t)
=(100×252)/(1600×9/4)
Rate of interest = 7% per annum.

2.(a)
Let first part = Rs. x and second part = Rs. (1750-x)
According to the question.
x×8/100=(1750-x)×6/100
8x + 6x = 1750 x 6
14x = 1750 x 6
x=(1750×6)/10=Rs.750
Interest = 8% of Rs. 750
= 750 × 8/100=Rs,750
= 750 × 8/100=Rs.60

3.(c)
Simple interest gained from Rs. 500
= (500×12×4)/100 = Rs. 240
Let the other Principal be Rs. x.
S.I. gained = Rs. (480 -240) = Rs. 240
(x×10×4)/100=240
x=(540×100)/40 = Rs. 600

4.(b)
Principal + SI for 2 years = Rs. 720 …..(i)
Principal + SI for 7 years = Rs. 1020 ….(ii)
Subtracting equation (i) from (ii) we get,
SI for 5 years
= Rs. (1020 -720) = Rs. 300
SI for 2 years = Rs. 300× 2/5= Rs. 120
Principal = Rs. 720- Rs. 120 = 600

5.(a)
Interest = Rs. (81-72) = Rs. 9
Let the time be t years.
9 = (72×25×t)/(4×100)
t=(9×400)/(72×25)=2 years

6.(d)
Let the sum be Rs. x
(x ×5 ×15)/(100 ×12)-(x ×4 ×8)/(100 ×12)=129
x/(100×12) (75-32)=129
x=(129×1200)/43= Rs. 3600


7.(a)
Let the rate of interest be R per cent per annum.
(400×2×R)/100+(550×4×R)/100+(1200×6×R)/100=1020
8R + 22R + 72R = 1020
102 R =1020
R = 1020/102=10%

8.(a)
Principal = P
Amount = 7p/6
S.I. = 7p/6-P=P/6
? R=(S.I×100)/(P×T)=(P×100)/(6×p×3)
= 50/9=5 5/9%

9.(a)

10.(a)
Rate = (SI ×100)/(Principal ×Time)
= 9/25×100/6=6% per annum