A certain sum amounts to ₹1,725 in 3 years and ₹1,875 in 5 years on simple interest. The interest rate per annum is:

Correct option is B

Given:

Amount in 3 years = ₹1725

Amount in 5 years = ₹1875

Formula Used:

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

Amount = Principle + Interest

Solution:

SI for two years = SI for 5 years - SI for 3 years

= 1875 - 1725 = ₹150

SI for one year =$$\frac{150}{2} =₹75$$​​

SI for 3 years = $$\frac{150}{2} =₹225$$​​

Principle = Amount - Interest = 1725 - 225 = ₹1500

​$$225 = \frac{ 1500 \times R \times 3}{100}$$​

​$$R = \frac{225 \times 100}{1500\times 3}$$​​

R = 5%