Answer:
10 weeks
Explanation:
400.25 - 115 = 285.25
So he really only needs $285.25. So then we have to divide 285.25 ÷ 31 to find out how many weeks it will take to get to $285.25
285.25 ÷ 31 = 9.2
But you have to round it up to the nearest week. So the answer would be 10 weeks