Rob works part time at the fallbrook riding stable. he makes $5 an hour exercising horses and $10 hour cleaning stalls. because rob is a full time student he can work no more than 12 hours per week. however he must make $60 per week. write a system of inequalitites

Let x be the number of hours exercising horses.
Let y be the number of hours cleaning stalls.

x + y <= 12
5x + 10y >= 60
x + 2y >= 12

At this point you might do well to graph this set of equations on Wolframalpha.com

In the meantime solve this system this way.

12 - x > y > 6 - x/2
When y =0 the x = 12.