Question

how long will it take 100 to reach 500 when its grows at 10 percent per year

Answer 1

The formula for annual compound interest, including principal sum, is:
A = P (1 + r/n) ^(nt)

Where:

A = the future value of the investment/loan, including interest = 500
P = the principal investment amount (the initial deposit or loan amount) = 100
r = the annual interest rate (decimal) = 10%
n = the number of times that interest is compounded per year = Yearly i.e 1
t = the number of years the money is invested or borrowed for = ?

500 = 100 (1 + 0.1/1) ^(1t)

500/100 = (1 .1) ^(t)

5 = (1.1) ^(t)

^{Using Calculatot ucan get}

^{t = 17}

^{Hence it will take 17 yeras to take 100 to reach 500.}