Answer:12 large t-shirtsStep-by-step explanation:Since all the values have multiples of 5 (i.e., 20, 1/5, and 3/5), let's envision a graphic that has 5 squares, each with a value of 4 t-shirts. Since there are 20 t-shirts in total, we'll add 5 squares to the graphic, each representing 4 t-shorts. See the attached graphic.1/5 of 5 boxes = 1 box of small1/5 of 5 boxes = 1 box of medium3/5 of boxes = 3 boxes of large(3 boxes of large)*(4 t-shirts/box) = 12 large t-shirts