Explanation:
Given that,
A gray crayon is made with 5 mL of black wax for every 6 mL of white wax.
We need to find the mixture will create the same shade of gray.
For this we need to make the ratio same.
If we multiply 5 mL and 6 mL by 3 to make the ratio same.
5 mL × 3 = 15 mL
6 mL × 3 = 18 mL
Hence, 15 mL of black wax mixed with 18 mL of white wax is mixed so as to make the ratio same.