Question

A club decides to sell T-Shirts for 15$ as a fund-raiser. It cost $20 plus $9 per T-Shirt to make them. How many T-Shirts need to be made to make a profit of at least $150?

Answer 1

The expression for T-shirt production is 20+9T
The expression for total price of selling the T-shirts is 15T

Profit = Total cost of selling - Total cost of buying
Profit = 15T - (20+9T)
Profit = 15T - 20 - 9T
Profit = 6T - 20 

To make profit ≥150

6T - 20 ≥ 150
6T ≥ 170
T ≥ 170/6
T ≥ 28.3

The minimum number of T-shirts needed is 29 T-shirts