A man deposited Rs. 2850 in a bank at 7% p.a. and Rs. 2150 in another bank at 9% p.a. Find the rate of interest for the whole sum.

7.86% 8.07% 7.93% 8.86%

7.86%

SI₁ = \(\frac{2850 × 7 × 1}{100}\) = 199.5         SI₂ = \(\frac{2150 × 9 × 1}{100}\) = 193.5        Total SI = 199.5 + 193.5 =  393 Rate = \(\frac{393}{5000}\) × 100 = 7.86%