If you deposit money today in an account that pays 15% annual interest, how long will it take to double your money? Round your answer to two decimal places.

It will take 4.96 year or 5 year to double the investment @ 15% interest rate.

Explanation:

Suppose you invest = P = $1

Double Investment = $2

Interest rate = r = 15%

Us following formula to calulate the number of year to make the investment double

A = P x (1 + r) ^n

$2 = $1 (1 + 0.15) ^n

$2 / $1 = (1.15) ^n

$2 = 1.15^n

log 2 = n log 1.15

n = log 2 / log 1.15

n = 4.96 years

It will take 4.96 year or 5 year to double the investment @ 15% interest rate.