Answer:
Yes, Nathan can use the coupon. $94.77 is the purchase cost after using coupon.
Explanation:
We are given the following information in the question:
Cost of 1 pairs of board short = $25.99
Cost of 3 pairs of board short =

Cost of 1 towel = $5.65
Cost of 2 towel =

Cost of 1 pair of sunglasses = $15.50
Total Cost =
Cost of 3 pairs of board short + Cost of 2 towel + Cost of 1 pair of sunglasses

Since, the total cost is greater than $100, Nathan can use the coupon.
Purchase cost after applying coupon =

$94.77 is the purchase cost after using coupon.