Answer:
The answer is that each shirt and pair of pants costs 15$
Explanation:
So you have 78$, and you already need to buy a backpack so then you have 60$ dollars because the backpack is 18$, and 2 shirts and 2 pairs of pants is 4 pieces of clothing in all, 60$ divided by 4 pieces of clothing equals 15$ per piece of clothing (78 - 18 = 60 divided by 4 = 15)