Story problem

Question

A store sold 36 T-shirts for a total of $522 in one day, some short-sleeved and some long sleeved. If short-sleeve T-shirts cost $12 each and long-sleeve T-shirts cost $18 each, then how many of each type of T-shirt were sold that day?

 

Please walk me through how to solve this problem

Thanks!

Answer 1

Hi Nick, let's figure this out!

 

You may solve this by setting up a system of linear equations.

 

Let S = the number of short-sleeved t-shirts sold

Let L = the number of long-sleeved t-shirts sold

 

You need an equation about the number of shirts sold:

 

S + L = 36

 

You need another equation about the value of shirts sold:

 

12S + 18L = 522

 

To solve by elimination, multiply the first equation by -12.

 

  -12S - 12L = -432

+ 12S + 18L = 522

 

Now add straight down (vertically):

 

6L = 90

L = 15

 

Replace L with 15 in either of the original equations. I used the first one.

 

S + L = 36

S + 15 = 36

S = 21

 

So, 15 long-sleeved t-shirts and 21 short-sleeved t-shirts were sold.