Problema Solution

If an amount of $10,000 is invested at continuous compounding, what rate of interest is necessary for the $10,000 to grow to $100,000 in 25 years

Answer provided by our tutors

P = $10,000 principal amount (initial investment)

r = annual interest rate (as a decimal)

t = 25 number of years

A = $100,000 amount after time t


A = Pe^(r*t)


e^(r*t) = A/P


r = (1/t) ln(A/P)


r = (1/25) ln(100,000/10,000)


r = (1/25) ln(10)


r = 0.0921 or 9.21%


9.21% annual rate of interest is needed.