Final answer:
The question involved a calculation of the duration of the loan based on the total interest paid and the monthly interest rate. By dividing $99 by the monthly interest of $5.50, the result indicated that it took 18 months to pay the interest, however, this does not match any of the provided options.
Step-by-step explanation:
The student is asking how long it took to pay off a loan with a given interest amount when the monthly interest rate is known. To solve this, we calculate the duration of the loan based on the total interest paid and the monthly interest rate.
The loan amount is $550 with a 1 percent monthly interest rate. The total interest paid is $99. To find the number of months it took to pay this interest, divide the total interest by the monthly interest amount:
Total interest: $99
Interest per month: $550 * 1% = $5.50
Duration (in months) = Total interest / Monthly interest
Duration (in months) = $99 / $5.50
Duration (in months) = 18 months
However, none of the given options match 18 months, indicating there might be a typo or misunderstanding in the question.