Shivam invests a sum of Rs. 5400 and Rupesh invests a sum of Rs. 9400 at the same rate of simple interest per annum. If, at the end of 4 years, Rupesh gets Rs. 600 more interest than Shivam, then find the rate of interest per annum (in percentage).

Correct option is C

Given:

Shivam invests Rs. 5400, and Rupesh invests Rs. 9400.

The time period is 4 years.

Rupesh gets Rs. 600 more interest than Shivam.

We need to find the rate of interest per annum.

Formula Used:

SI = $$\frac{P \times R \times T}{100}$$​​

Where:

P is the principal amount,

R is the rate of interest per annum,

T is the time period in years.

Solution:

SI for Shivam;

$$SI_1 = \frac{5400 \times R \times 4}{100} = \frac{21600R}{100} = 216R$$

SI for Rupesh;

​$$SI_2 = \frac{9400 \times R \times 4}{100} = \frac{37600R}{100} = 376R$$​​

Now, 

376R - 216R = 600

160R = 600

R = $$\frac{600}{160}$$​ = 3.75

Thus, the rate of interest per annum is 3.75%.