SOLUTION: A painter can paint a wall in 20 minutes. Working alone, the painter's apprentice can can paint the wall in 30 minutes. How long will it take them to painte the wall together?

You can put this solution on YOUR website!
10 min.
Explanation: If painter a can paint in 20 min, and painter b can paint in 30 min,if they want to paint one wall together it probably will take 10 min because 2 walls equal 50 min total thats adding so if they want to do one wall together you reverse the signs. SUBTRACT IT.