The simple interest on Rs.750 increases by Rs35 when the time increases by 2 years. Find the rate of interest per annum.

5% 2.5% 4.5% 3.33%

2.5%

The increase in interest is due to time ⇒ \(\frac{700\;×\;2\;×\;rate}{100}\) = 35 ⇒ Rate = 2.5%