Your question is missing some elements but to answer the question I have to make an assumption.
Assuming that she make a monthly payment of $75.
The value of an loan at the end of the two year is given by
where PV = $799, r = 7.2% = 0.072 and n = 2 years.
Thus,
If she makes a monthly payment of $75, the number of months it will take her to pay off for her laptop is given by
Therefore, it will take her 13 months to pay off for the laptop.
Assuming that she make a monthly payment of $75.
The value of an loan at the end of the two year is given by
where PV = $799, r = 7.2% = 0.072 and n = 2 years.
Thus,
If she makes a monthly payment of $75, the number of months it will take her to pay off for her laptop is given by
Therefore, it will take her 13 months to pay off for the laptop.