Question

A man got Rs. 130 less, as simple interest,
when he invested Rs. 2000 for 4 years as
compared to investing Rs. 2250 for same
duration. What is the rate of interest ?​

Answer 1

the rate of interest is 23.66

Answer 2

Given:

First principal = Rs. 2000

Second principal = Rs. 2250

Time = 4 years for both investments.

A man got Rs. 130 less in first investment as compared to second investment.

To find:

The rate of interest.

Solution:

Formula for simple interest is

$I=P\times r\times t$

where, P is principal, r is rate of interest and t is time in years.

Let the rate of interest be r%.

Simple interest for first investment is

$I_1=2000\times \dfrac{r}{100}\times 4$

$I_1=80r$

Simple interest for second investment is

$I_2=2250\times \dfrac{r}{100}\times 4$

$I_2=90r$

According to the question,

$I_2-I_1=130$

$90r-80r=130$

$10r=130$

Divide both sides by 10.

$r=13$

Therefore, the rate of interest is 13%.