Carmen auto shop...

Question

At Carmen's auto shop, it takes her 9 minutes to do an oil change and 15 minutes to do a tire change. Let x be the number of oil changes she does. Let y be the number of tire changes she does.

Using the values and variables given, write an inequality describing how many oil changes and tire changes Carmen can do in less than an hour (60 minutes).

Answer 1

Chance, don't let all the words get in the way. The number of oil changes  If we want to know how long it would take Carmen to do 8 oil changes, we'd multiply 9 minutes x 8 oil changes = 72 minutes, right?

 

We are letting x = the number of oil changes, so 9x = the total time to do x oil changes.

 

If y = the number of tire changes, then Carmen's total time to do y changes is 15y.

 

We want to know how many of each Carmen can do in less than 60 minutes.

 

9x + 15y < 60. It's not <1, because we are dealing in minutes and not hours.

 

Hope this helps!