Mr.Schwartz begins the week with = 85 wheels
Number of wheels used per car = 4
He orders more wheels when less than 40 wheels are left.
Given inequality is = x<40
The minimum number of wheels he can use before ordering more wheels= ![85-40=45](https://tex.z-dn.net/?f=85-40%3D45)
So, 45 minimum 45 wheels can be used before ordering more wheels.
4 wheels are used to make = 1 car
45 wheels are used to make =
cars
If 12 cars are to be build then wheels required will be = ![12\times4=48](https://tex.z-dn.net/?f=12%5Ctimes4%3D48)
Beginning number of wheels = 85
Wheels used for making 12 cars = 48
Wheels left = ![85-48=37](https://tex.z-dn.net/?f=85-48%3D37)
But as mentioned, Mr. Schwartz orders wheels if they are less than 40, so after building 12 cars, 37 wheels will be left and he will order more.