Question

If a sum of money compounded annually becomes 1.44 times of itself in 2 years, then the rate of interest per annum is

Answer 1

P = principal
Sum accumulated = S = P (1 + r/100)² = 1.44 P
   =>  1 + r/100 = 1.2
   => r = 20 %

Answer 2

 S = P (1 + r/100)² 
given that the sum of the money compounded annually becomes 1.44 times of itself in 2 years
1.44P = P(1+r/100)²
1+r/100 = √1.44 (by taking LCM)
100+r/100 = 1.2
100+r = 1.2×100
100+r = 120
r = 120-100
r = 20 percentage