Question

Emely spent $320 on shirts. Designer shirts cost $40, and plain shirts cost $12. If she bought a total of 15, how many designer shirts did she buy?

Answer 1

She bought 5 designer shirts.

Explanation:

Let d=designer shirts and p=plain shirts

create the following equations

Total shirts. d + p = 15

Total cost 40d + 12p = 320

use the first equation and solve for p and substitute into the second equation and solve for d

p=15-d

40d + 12(15-d) = 320

40d + 180 -12d = 320

28d = 140

d = 5