Rakesh invests a sum of Rs. 5400 and Shivam invests a sum of Rs. 10200 at the same rate of simple interest per annum. If, at the end of 4 years, Shivam gets Rs. 480 more interest than Rakesh, then find the rate of interest per annum (in percentage).

Correct option is A

Given:

Rakesh's principal = Rs. 5400

Shivam's principal = Rs. 10200

Time = 4 years

Shivam’s interest is Rs. 480 more than Rakesh’s

Same rate of simple interest for both

Formula Used:

Simple Interest (SI) = $$\frac{P \times R \times T}{100}$$​​

Solution:

Let rate = R%

Interest of Rakesh:

SI1 = $$\frac{5400 \times R \times 4}{100} = 216R$$​​

Interest of Shivam:

SI2 = $$\frac{10200 \times R \times 4}{100} = 408R$$​​

Now, 

408R - 216R = 480

192R = 480

R = $$\frac{480}{192} = 2.5 \%$$​​