Answer:
R8000.
Explanation:
First, let's calculate the amount they are going to have to pay the bank after 1 year. It is given by the following expression:
R5 000 * 1.28= R6400
Therefore, they have to pay R6400/12 monthly.
Now, in fifteen months the total amount to pay should be (R6400/12) * 15= R8000.