Graphing Linear Equations, Word Problem

A factory assembles two types of motors, small and large.

The cost of material is $15 for a small motor, and $30 for a large motor.

Two hours of labor are needed to assemble a small motor and six hours for a large.

The cost of labor is $8/hour.

The owner can allocate at most $1500/day for material and $2000/day for labor.

Find the largest daily profit that the owner can make if the small motors are sold for $40 each and the large motors for $104 each. Assume every motor produced is sold.

So far I have :

x=small motors y=large motors

x > 0

y > 0

15x+30y < 1500

y < -1/2x+50

Currently I'm stumped on the part of the equation that would determine the cost of labor.