Since 30 isn't a factor of 45, lets find a factor for 45. Since 15 is a factor, we can divide 30 by 2 to get 15, but divide by 2 by 90, since we need to keep the rate. Now, DeShawn can paint 45 feet of fences in 15 min. Multiply both numbers by 3 to get 135 feet of fences in 45 min.
