F(2y + 1) is 2
+
for this question
The third one is the right one on e2020
If one shirt equals to $21.46, and you need to purchase 4 shirts to get the free pair of jeans, you multiply 4 by 21.46 and get 85.84. But if there is 42 customers taking advantage of the special, then you need to multiply 85.84 by 42, and you get 3,605.28.
