Answer:

b) The cost of 11 T-shirts during bargain days is $85.75
Explanation:
We are given the following information in the question:
Discounted cost of one T-shirt = $8.25
Additional off on coupon = $5.00
Let t be the number of T-shirts bought during the bargain days.
a) Then, the price of t T-shirts with the discount applied will be given by the function:

b) Price during Bargain Days for 11 shirts
We put t = 11 in the above function:

Thus, the cost of 11 T-shirts during bargain days is $85.75