The turtle swims at a speed of 21,120 yards per minute (12 x 5280 = 63,360, 63,360/3 = 21,120) and the boy swims at a speed of 88 yards per minute. So the turtle swims 21,032 yards per minute faster than the boy.
The current area is 12x4 which is 48yards^2. 60 percent of that is 48x0.4=19.2. Now you can just put some random numbers that when multiplied = 19.2. For ex. 2 and 9.6, 4 and 4.8.