Answer:
12 years
Step-by-step explanation:
Simple interest formula:
[tex]I=P\cdot r\cdot t,[/tex]
where
I = interest,
P = principal,
r = rate (as decimal),
t = time
In your case,
P = $616
I = $1,007.78 - $616 = $391.78
r = 0.053
t - unknown, so
[tex]391.78=616\cdot 0.053\cdot t\\ \\t=\dfrac{391.78}{616\cdot 0.053}\approx 12[/tex]
