How do I solve this?

Question

A high school chargers $1 for student tickets to their musical production. They charge $3 for non student tickets. If they made a total of $376 and sold a total of 232 tickets, how many of each type of ticket did they sell.

Answer 1

s + n = 232

s + 3n = 376

s + n = 232

subtract

2n = 144

n = 72 non student tickets

s = 232-72 = 160 student tickets

160 + 3(72) = 160+216 = 376 revenue