All you really have to do is multiply 1/5 and 3/4. We can separate her backyard in 5 equal parts. In one of those parts, we have her garden, and we break it down into 4 pieces, and make three of those tomato gardens. Now if we break all 5 parts of her backyard into 4 pieces, we can double check our answer, and see that there are 20 pieces, but only 3 have tomatoes. Of course, that's only to double check, but you could also use this method as a model.
