Answer:
11 weeks
Explanation:
If we multiply 50 by 11 we get 550 with a remainder of 100, if we're to take out another 50 for another week we would have 50 dollars remanding but the question says that we need to have at least 75 remaining so this will not be possible. Therefor 11 weeks is our answer.
I hope this helps have a great day :)