Answer:
4.5 years
Explanation:
The computation of the number of years is shown below:-
Future value = Present value × (1 + interest rate)^n umber of years
$ 66,610.25 = $40,000 × (1 + 0.12)^n
$1.665256 = (1.12)^n
LN 1.665256 = n LN 1.12
0.509979 = n × 0.113329
n = 4.499
or
= 4.5 years
Therefore for computing the number of years we simply applied the above formula.