How many years will it take to reach 18600 if Tina invests 1000 in an account that pays 6.5 percent interest?

Assuming compound interest at 6.5% compounded annually

1000(1.065)^n = 18600
1.065^n = 18.6
log 1.065^n = log 18.6
n log 1.065 = log 18.6
n = log 18.6 / log 1.065 = appr 46.4 years