A company purchased 1000 lightbulbs. Headlights cost $13.95 each and tailights cost $7.55 each. If the company spent $9342 on lightbulbs, how many of each did t

Question

I found out what the answer to this problem was in the back of the book but I can't seem how to figure out how they solved it.

Answer 1

Hi Karmen.

 

Here is what we know:
Headlights (h) = $13.95 ea.

Tailights (t) = $7.55 ea.

x = number of headlights bought

y = number of tailights bought

 

x + y = 1000

x*h + y*t = $9342

 

y = 1000 - x

Therefore we substitute:
13.95x + 7.55(1000-x) = $9342

13.95x + 7550 - 7.55x = $9342

6.4x = 9342 - 7550

6.4x = 1792

x = 280 headlights

y = 720 tailights