It takes DeShawn 30 min to paint 90 feet of fence. If he paints at the same rate, how many feet of fence can he paint in 45 minutes?

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.