# CCSS IP Math I 1.4.1 Example 4

- Topic:
- Inequalities

A school supply company produces wooden rulers and plastic rulers. The rulers must first be made, and then painted.

- It takes 20 minutes to make a wooden ruler. It takes 15 minutes to make a plastic ruler. There is a maximum amount of 480 minutes per day set aside for making rulers.
- It takes 5 minutes to paint a wooden ruler. It takes 2 minutes to paint a plastic ruler. There is a maximum amount of 180 minutes per day set aside for painting rulers.

- We know from this situation that you cannot produce a negative amount of rulers, so none of our solutions can be negative.
- In future lessons, we discuss more precise ways of determining the solution set to a system. For now, we can use our knowledge of numbers and ability to solve algebraic sentences to find possible solutions.
- Choose a value for
*w*. Substitute the value for each occurrence of*w*in the system and solve for*p*. - Interpret the results.