To find the number of years it takes for an investment to grow to a certain value at a certain interest rate, you can use the formula:
n = (future value - principal) / (principal * interest rate)
Where:
n = number of years
future value = the final value of the investment
principal = the initial amount invested
interest rate = the annual interest rate as a decimal
Plugging in the given values:
n = (21150 - 5000) / (5000 * 0.17)
n = 16.65
Rounding to the nearest whole number, it would take approximately 17 years for the investment to be worth $21,150.00.