Answer:
Assuming the question is how much interest you will pay in the given time frame with the given terms.
Explanation:
Borrowed $300
18% per yr = 18/12 = 1.5% per month
You borrowed for 6 months so you will end up paying 1.5%*6 =9% in interest
$300*(9% or 0.09) = $27 in interest paid + $300 in principal paid if paid off in 6 months.
Total $327.
If this was an economics class you would also have to factor in the depreciation of the principal amount month to month with minimum payments but I am guessing this is just a basic question so the above answer is correct enough.