# Quantitative Aptitude: Simple/Compound Interest Set 08

Simple Interest/Compound Interest Questions for IBPS PO, SBI PO, NIACL, NICL, LIC, UICL, Bank of Baroda and other competitive exams.

1. Out of a sum of Rs 850, a part was lent at 6% SI and the other at 12% SI. If the interest on the first part after 2 years is equal to the interest on the second part after 4 years, then the second sum is
A) Rs350
B) Rs280
C) Rs170
D) Rs220
E) None
Option C
Solution:

Let the first part be x then second part be 850-x.
(x*6*2)/100 = [(850-x)*12*4]/100
x= 850*4 -4x
5x=850*4
x=680
Then second part 850-680=Rs 170.
2. A sum of Rs. 550 was taken as a loan. This is to be paid back in two equal installments. If the rate of interest be 20% compounded annually, then the value of each installment is :
A) Rs360
B) Rs280
C) Rs250
D) Rs320
E) None
Option A
Solution:

Let x = equal installment at the end of one year( rate% annually) .
Now 1st year,
P =550,
Interest = (550*20*1)/100 = 110.
Now, at the beginning of 2nd year,
P =550 + 110 – x
Interest at the end of 2nd year,
= [(660 – X) *20*1]/100 = 132 –x/5.
Hence,total installment,
2x = 550 + 110 + 132 – x/5
2x + x/5= 792
x = 360.
3. A certain sum of money amounts to Rs.1300 in 2 years and to Rs. 1525 in 3.5 years. Find the sum and the rate of interest.
A) Rs850, 10%
B) Rs900, 12%
C) Rs800, 13%
D) Rs1000,15%
E) None
Option D
Solution:

1525-1300= 225 for 1.5 yrs (3.5-2)
so for one yr 225/1.5= 150
then for 2 yrs interest is 150+150=300
Then principal 1300-300=1000.
Now 150/1000*100= 15%
4. The simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 4000 for 2 years at 10% per annum. The sum placed on simple interest is:
A) Rs1800
B) Rs1750
C) Rs2000
D) Rs1655
E) None
Option B
Solution:

CI =[4000 *(1 + 10/100)2 – 4000] =4000*11/10*11/10 – 4000
=Rs840.
Then Sum in SI 420 (ie840/2)= (P*3*8)/100
=Rs1750.
5. A Woman took a loan of Rs. 15,000 to purchase a mobile. She promised to make the payment after three years. The company charges CI at 20% per annum for the same. But, suddenly the company announces the rate of interest as 25% per annum for the last one year of the loan period. What extra amount she has to pay due to the announcement of new rate of interest?
A) Rs1230
B) Rs1135
C) Rs1080
D) Rs1100
E) None
Option C
Solution:

15,000 *(1+20/100)2[ (1+25/100) – (1+20/100)] 15,000*120/100*120/100 [125/100-120/100] 15000*144/100(5/100)
150*144*5/100=1080
6. The ratio of the amount for two years under compound interest annually and for one year under simple interest is 6:5. When the rate of interest is same, then the value of rate of interest is:
A) 20%
B) 15%
C) 18%
D) 22%
E) None
OptionA
Solution:

[P(1+r/100)2]/[P(1+r*1/100)]=6/5
1+r/100=6/5
r/100=1/5
r=20%
7. An automobile financier claims to be lending money at simple interest, but he includes the interest every six months for calculating the principal. If he is charging an interest of 10%, the effective rate of interest becomes:
A) 9.5%
B) 8%
C) 10.25%
D) 10%
E) None
Option C
Solution:

Let the sum be Rs. 100. Then,
S.I. for first 6 months = 100*10*1/100*2 =Rs5
S.I. for last 6 months = 105*10*1/100* 2 =Rs5.25
So, amount at the end of 1 year = Rs. (100 + 5 + 5.25) = Rs. 110.25
Effective rate = (110.25 – 100) = 10.25%
8. A person borrows Rs. 3000 for 2 years at 5% p.a. simple interest. He immediately lends it to another person at 6 ¼ %p.a for 2 years. Find his gain in the transaction per year.
A) Rs42
B) Rs39.25
C) Rs35
D) Rs37.5
E) None
Option D
Solution:

Gain in 2 yrs =[(3000*25/4*2/100)-(3000*2*5/100)] 375-300=75.
Gain in 1yr=75/2=37.5
9. If the difference between CI and SI earned on a certain amount at 20% pa at the end of 3 years is Rs.640, find out the principal.
A) Rs5500
B) Rs6500
C) Rs4500
D) Rs5000
E) None
Option D
Solution:

SI-CI for 3 yrs =Pr2/1003*(300+r)
640=P*202/1003*320
640=(P*20*20/100*100*100)*320
P=Rs5000
10. If the simple interest on a certain sum of money is 4/25 of the sum and the rate per cent equals the number years, then the rate of interest per annum is:
A) 4%
B) 5%
C) 8%
D) 10%
E) None
Option A
Solution:

Let the principal be Rs x.
Then the SI =4/25x
Rate of interest = Time
r= (100*4/25x)/ x*r
r2 =400/25
r=20/5=4%

## 5 Thoughts to “Quantitative Aptitude: Simple/Compound Interest Set 08”

1. Always smile

ty:))

2. DHANANJAY

9/10 ty mam:))

1. karthik

bro plz explain 2nd one

1. AmRITa @ bank po

Installment for CI has a rule..let x be amount paid in installment..then
P=x/(1+r/100)+x/(1+r/100)2..
For 2 years..now put formula and get answer..

3. kumkum ahuja

ty mam:)