Answer:
x = 22.22 minutes
Explanation:
No tables were included.
Here's how to solve
1polish/40min + 1polish/50min = 1 polish/x minutes
1/40 + 1/50 = 1/x
use 200 as common denominator
5/200 + 4/200 =9/200
9/200 = 1/x
Cross multiply
9x = 200
Divide both sides by 9
x = 200/9
x = 22.22 minutes