Question

a principle amount becomes double in 15 years at compound interest.find the rate of interest

Answer 1

p=1
A=2(priniciple)=2
n=15year
r=?
A=p(1+r/100)^n
2=1(1+r/100)^15
2^(1÷15)=1+r/100
1.04729-1=r/100
0.04729×100=r
r=4.72%