We are told that Carrie borrows $960 interest free to pay for a car repair. She will repay $120 monthly until the loan is paid off and we are asked to find how many months will it take Carrie to pay off the loan.
In order to find out the number of months to pay off the loan we will divide total amount borrowed by monthly loan installment.
Therefore, Carrie have to pay $120 for 8 months to payoff the loan.