# Simple interest questions

Simple interest questions involve calculating the interest earned or paid on a principal amount over a specified period, which is essential in quantitative aptitude questions. In this article, we added few simple interest questions to mold your problem-solving aptitudes and time management skills needed for Kerala PSC, SSC, Banking, and another comitative test. Find the repeated questions below and practice now!

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

Principal + SI for 2 years = 720 Rs. ……(I)
Principal + SI for 7 years = 1020 Rs. ……(II)
Subtracting equation (I) from (II),
S.I. for 5 years = $(1020 – 720) = 300$ Rs.
The, S.I. for 2 years = $300\times \frac{2}{5} = 120$Rs.
∴ Principal = $(720 – 120) = 600$ Rs.

1. What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years?

$\frac{PR\times 6}{100}:\frac{PR\times 9}{100}$
6:9=2:3

1. The difference between the simple interest received from two different sources on Rs.2000 for 4 years is Rs.16. The difference between their rates of interest is:

P = 2000 , N = 4 , R = difference between rates

I = 16

$I = PNR$

16= $\frac{2000\times4\times R_1}{100}$-$\frac{2000\times4\times R_2}{100}$

$16= 80(R_1-R_2)$

R = 0.2%

1. The difference between the simple interest received from two different sources on Rs. 5200 for $2 \frac{1}{2}$yr is Rs.65. The difference between their rates of interest is

$[5200 \times \frac{5}{2} \times \frac{x}{100}] - [5200 \times \frac{5}{2} \times \frac{y}{100}] = 65$

$130x- 130y = 65$

$130(x-y)= 65$

On solving, x-y = 0.5

1. The difference between the simple interest received from two different banks on Rs. 750 for 2 years is Rs. 135. Find the difference between their rate of interest ?

Given:

The difference between the simple interest received from two different banks on Rs. 750 for 2 years = Rs. 135

Formula used:

Simple interest $= \frac{P × R × T}{100}$

Where, P → Principal

R → Rate

T → Time

Calculation:

Let the rate of interest be R and r.

Simple interest =$\frac{P × R × T}{100}$

According to the questions,

$(\frac{P × R × T}{100}) – (\frac{P × r × T}{100}) = 135$

$⇒ (\frac{750 × R × 2}{100}) – (\frac{750 × r × 2}{100}) = 135$

$⇒ (15R) – (15r) = 135$

$⇒ 15(R – r) = 135$

$⇒ (R – r) = 9$%

∴ The difference between their rate of interest is 9%.