Answer:
$3,545
Explanation:
PV = 3990
APR = .139
PV = $3,990 = $50 × (1 - {1 / [1 + (.139 / 12)]t}) / (.139 / 12)
t = 224.16 months.
PV = $3,990 = $60 × (1 - {1 / [1 + (.139 / 12)]t}) / (.139 / 12)
t = 127.72 months.
Additional cost = (224.16 ×$50) - (127.72 ×$60) = $3,545
It will cost Jake $3,545 to pay off his balance, if he makes monthly payments of $50 rather than $60.