Question

Which inequality models this problem?

Harry has found two companies that can make custom shirts for him and his friends. Company A charges $12 per shirt plus a $40 design fee. Company B charges $16 per shirt with no design fee.

What is the minimum number of shirts Harry will need to buy for the cost to be less at company A than company B?

A) 12x-40<16x
B) 12x+40<16x
C) 12x-40>16x
D) 12x+40>16x​

Answer 1

The inequality is B 12x + 40 < 16.

The minimum number of shirts is 11.

Explanation:

Let x = number of shirts

Company A:

$12 per shirt + $40 fee

cost = 12x + 40

Company B:

$16 per shirt

cost = 16x

cost of A < cost of B

12x + 40 < 16x

-4x < -40

x > 10