A man invested in two schemes. In 2 years from scheme A, which offered compound interest at 20% per annum he gets total interest of Rs. 3520. If man invested total amount received from scheme A in scheme B which offered simple interest at 10% for 3 years, then find what will be the interest gained by man from scheme B?

Scheme A: Compound interest at 20% for 2 years, interest = Rs. 3520. Using compound interest formula: CI = P[(1+r)^n - 1] = P[(1.2)^2 - 1] = P[1.44-1] = 0.44P. So 0.44P = 3520, P = 3520/0.44 = Rs. 8000. Amount from Scheme A = 8000 + 3520 = Rs. 11520. Scheme B: Simple interest on Rs. 11520 at 10% for 3 years. SI = P×r×t = 11520 × 0.1 × 3 = Rs. 3456. Option B is correct.