You have 5000 toward the purchase of a boat that will cost 6

You have $5,000 toward the purchase of a boat that will cost $6,000. How long will it take the $5,000 to grow to $6,000 if it is invested at 9% compounded quarterly? (Round up to the next-higher quarter if not exact).

Solution

formula is A=P{1+r/100}^n

6000=5000{1+0.09/4}^n

6/5=(4.09/4)^n

taking log

log 6/5=n log 4.09/4

n=8.19

hence 8/4=2 years