Calculate the number of years for an investment of $1000 to double at an interest rate of 7.2% for each period

Question

Calculate the number of years for an investment of $1000 to double at an interest rate of 7.2% for each compounding period

A) ANNUALLY
B) SEMI-ANNUALLY
C) MONTHLY
D) DAILY


plz show steps ... and formula in the form ... f(x)= a(2)^t/n ..... (where 'n' is the doubling time) ... thnku ... =)

Answer 1

total/inv = (1+int/per)^(n*per); left side =2

Take natural log of both sides ans solve for n