Find the rate at which a sum of money will double itself in 3 years, if the interest is compounded annually.
Let Principal (P)=Rs. 100
then Amount(A)=Rs. 200
Period(t)=3 years.
Let R be the rate %.
Since, we have A=P(1+R100)3
Substitute given values, we get
⇒200=100(1+R100)3
⇒200100=(1+R100)3
⇒3√2=(1+R100)
⇒1.2599=1+R100
⇒R100=1.2599−1
⇒R=0.2599×100
∴R=25.99% per annum.