Question 1210372
<pre>
Another way to look at it is what they COULD do in the same time.

Painter A can paint a wall in 60 minutes and painter B can paint the same wall in
120 minutes.  Therefore,

painter A COULD paint 2 walls in 120 minutes while painter B COULD paint only 1
wall in that same 120 minutes, so in 120 minutes together they COULD paint 3
walls, so to paint only 1 wall it would take them only 1/3 of 120 minutes or 40
minutes.

Edwin</pre>