Rakesh invests a sum of ₹5,000 and Shivam invests a sum of ₹9,000 at the same rate of simple interest per annum. If, at the end of 3 years, Shivam gets ₹360 more interest than Rakesh, then find the rate of interest per annum (in percentage).

Correct option is C

Given:

Principal of Rakesh $$P_1=₹5$$​000, Shivam P$$_2=₹9000$$​; time t = 3 years; same simple interest rate (r%).
Shivam’s interest exceeds Rakesh’s by ₹360.

Formula Used:
Simple Interest SI=$$\dfrac{P\times r\times t}{100}$$​​

Difference in SI $$=\dfrac{(P_2-P_1)\times r\times t}{100}$$​​

Solution:
36$$0=\frac{(9000-5000)\times r \times 3}{100}$$​​
​$$360=\frac{4000\times 3 \times r}{100}=120r$$​​
r$$=\frac{360}{120}=$$​3%