Simple and Compound Interest Aptitude Questions and Answers with Detailed Solution:
Question No. 01
A sum
fetched a total simple interest of Rs. 4016.25 at the rate of 9% p.a. in 5
years. What is the sum?
(A) Rs.
4462.50
(B) Rs.
8032.50
(C) Rs. 8900
(D) Rs. 8925
Answer:
Option D
Explanation:
Principal =
Rs. (100 × 4016.25)/(9 × 5)
= Rs. (401625/45) = Rs. 8925.
Question No. 02
Calculate
the amount on Rs. 4480 at 8% per annum for 3 years.
(A) Rs.
5555.20
(B) Rs. 5545.20
(C) Rs. 5000
(D) Rs. 6555
Answer:
Option A
Explanation:
S.I. = (P × N
× R)/100
= Rs. (4480 × 3 × 8)/100
= Rs. 1075.20
∴ Amount
= Rs. (4480 + 1075.20)
= Rs. 5555.20
Question No. 03
A certain
sum of money at simple interest amounts to Rs. 1260 in 2 years and to Rs. 1350
in 5 years. The rate percent per annum is?
(A) 35 %
(B) 25 %
(C) 50 %
(D) 45 %
Answer:
Option B
Explanation:
S.I. for 3
years = Rs. (1350 - 1260) = Rs. 90
∴ S.I.
for 2 years = Rs. (90/3) × 2 = Rs. 60
Principal =
Rs. (1260 - 60) = Rs. 1200
Rate, R = (100
× 60)/(1200 × 2) % = 25 %
Question No. 04
Mr. Roy
invested an amount of Rs. 13,900 divided in two different schemes A and B at
the simple interest rate of 14% p.a. and 11% p.a. respectively. If the total
amount of simple interest earned in 2 years be Rs. 3508, what was the amount
invested in Scheme B?
(A) Rs. 6400
(B) Rs. 6500
(C) Rs. 7200
(D) Rs. 7500
Answer:
Option A
Explanation:
Let the sum
invested in Scheme A be Rs. x and that in Scheme B be Rs.
(13900 - x).
Then, [x ×
14 × 2)/100] + [{(13900 - x) × 11 × 2}/100] = 3508
=> 28x -
22x = 350800 - (13900 × 22)
=> 6x =
45000
=> x =
7500.
So, sum
invested in Scheme B = Rs. (13900 - 7500) = Rs. 6400.
Question No. 05
How much
time will it take for an amount of Rs. 450 to yield Rs. 81 as interest at 4.5%
per annum of simple interest?
(A) 3.5
years
(B) 4 years
(C) 4.5
years
(D) 5 years
Answer:
Option B
Explanation:
Time = [(100
× 81)/( 450 × 4.5)] years = 4 years.
Question No. 06
A sum of Rs.
725 is lent in the beginning of a year at a certain rate of interest. After 8
months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At
the end of the year, Rs. 33.50 is earned as interest from both the loans. What
was the original rate of interest?
(A) 3.6%
(B) 4.5%
(C) 5%
(D) None of
these
Answer:
Option D
Explanation:
Let the
original rate be R%. Then, new rate = (2R)%.
Here,
original rate is for 1 year(s); the new rate is for only 4 months i.e. for 1/3
year.
∴
[(725 × R × 1)/100] + [362.50 × 2R × 1)/(100 × 3)] = 33.50
=> (2175
+ 725) R = 33.50 × 100 × 3
=> (2175
+ 725) R = 10050
=> (2900)
R = 10050
=> R = (10050/2900)
= 3.46
∴ Original
rate = 3.46%
Question No. 07
A certain
amount earns simple interest of Rs. 1750 after 7 years. Had the interest been
2% more, how much more interest would it have earned?
(A) Rs. 35
(B) Rs. 245
(C) Rs. 350
(D) Cannot be
determined
Answer:
Option D
Explanation:
We need to
know the S.I., principal and time to find the rate.
Since the
principal is not given, so data is inadequate.
Question No. 08
Ravi took
a loan of Rs. 1200 with simple interest for as many years as the rate of
interest. If she paid Rs. 432 as interest at the end of the loan period, what
was the rate of interest?
(A) 3.6
(B) 6
(C) 18
(D) None of
these
Answer:
Option B
Explanation:
Let rate =
R% and time = R years.
Then, (1200 ×
R × R)/100 = 432
=> 12R2 =
432
=> R2 =
36
=> R = 6.
Question No. 09
S.I. on Rs.
1500 at 7% per annum for a certain time is Rs. 210. Find the time;
(A) 3 years
(B) 5 years
(C) 2 years
(D) 1½ years
Answer:
Option C
Explanation:
Time, N = (210
× 100)/(1500 × 7) = 2 years
Question No. 10
A sum of
money at simple interest amounts to Rs. 815 in 3 years and to Rs. 854 in 4
years. The sum is:
(A) Rs. 650
(B) Rs. 690
(C) Rs. 698
(D) Rs. 700
Answer:
Option C
Explanation:
S.I. for 1
year = Rs. (854 - 815) = Rs. 39.
S.I. for 3
years = Rs. (39 × 3) = Rs. 117.
∴ Principal
= Rs. (815 - 117) = Rs. 698.
Simple and Compound Interest Next Tests: