help me with this math problem?

Question

$9000 has been invested in an account paying 7.87% annually, compounded monthly.

How long will it take for the investment to exceed 12031?

Your answer should be accurate to one decimal place.

Approximately ________years

Answer 1

Amount = 9000(1+0.0787/12)^t with t in monts
ln(12031/9000)/ln(1.0066) = 44.1 month
so it would take 44.2 month to exceed
in years 3.7 years

Answer 2

9000(1+7.87/100/12)^n=12031 n is number of months
1.006558^n=12031/9000=1.3368
taking log both sides we get
n=log 1.3368/log 1.006558
n=44.4 months= 3yrs 9mnths