A sum of ₹10,000 becomes ₹14,400 on compound interest in 2 years. What is the rate of interest per annum?

10% 40% 20% 15%

20%

Principal, P = 10000 Amount, A = 14400 time, t = 2 years A = $P (1+r%)^t$ = $10000 (1+r%)^2$ = 14400 $(1+r%)^2$ = 1.44 (1+r%) = 1.2 r% = 1.2-1 = 0.2 r/100 = 0.2 r = 20% The correct answer is Option (3) → 20%