Give the step-by-step reasoning process and then the final answer. Grover bought 3 boxes of face masks. He plans to sell them for $0.50 each. If each box has 20 face masks, and he bought the 3 boxes for $15, how much will be his total profit?
Grover will earn $0.50 x 20 = $10 for each box. So, he will earn $10 x 3 = $30 after selling all the face masks. Therefore, his total profit will be $30 - $15 = $15.
The final answer: 15.