All members of our painting team paint at the same rate. If $10$ members can paint a $100$ square foot wall in $10$ minutes, then how long would it take the $15$ members to paint a $100$ square foot wall, in minutes?
10 members paint 10 sq ft in one minute
So
1 member paints 1 sq ft in one minute
15 paint 15 sq ft / min
100 / 15 = 6 + 10/15 = 6 + 2/3 min
+456 
