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?
100 ft^2 / ( 10 m * 10 p) = 1 ft^2 / 1 m - p each square foot requires 1 people minute
100 ft^2 * 1 p m / ft^2 / 15 p = 6 2/3 minutes