If $6,000 is placed in an account with an annual interest rate of 3.5%, how long will it take the amount to quadruple if the interest is compounded annually? round your answer to two decimal places.

To calculate the amount after 1 year multiply by 1.035 for each year
e.g. in the first year 6000*1.035= 6210
after second year 6210*1.035 = ...
keep doing that till you get a number equal or greater than 24000, however many times you multiply by 1.035 is how many years it will take