Thong opened a compound interest account. He made an initial deposit of $1,280. The account pays him 3.6% annual interest and is compounded annually. If Thong doesn't make any other deposits into this account, how many years will it take for the balance in Thong's account to be $2,000 ? Here is the Balance Function for a compound interest account. B(t)=P(1+nr)nt Round your answer to the nearest tenth of a year. Input only the number. For example: 10.3