White and solve a system of inequalities to model the following situation:
A retail store manager makes comty cloth facemasks for his employees during covid.
He has enough money to buy $100 worth of fabric.
Fabric costs $4 for a single layer mask and $6 for a mask with 2 layers of fabric.
It takes him 30 minutes to make a single layer mask and 1 hour to make double layer mask.
He only has 15 hours available to work on masks.
He wants to maximise his time and resources.
How many of each type of mask should he make