First, we need to convert the loan repayment period to the same unit as the interest rate. The interest rate is 7% per year, which is equivalent to 0.07/12 = 0.00583 per month.
The total interest paid is given by:
interest = principal x rate x time
Where principal is the amount of the loan, rate is the interest rate per month, and time is the loan repayment period in months.
Substituting the given values, we get:
interest = $600 x 0.00583 x 9
interest = $31.35
Therefore, Emma will pay a total interest of $31.35 on the loan.