Answer:
1) We know that tomatoes cost 56c per the pound, and he estimates that he bought 5 pounds of tomatoes. If we multiply 5 by 0.56 we get 2.8, which means that if he purchased 5 pounds of tomatoes, he would have spent only 20c more than he did, which is pretty close. So yes, his estimate is reasonable
2) Well, i dont hav any clear amount of money he can spend so, just remember, if you have 3 pounds per say, you multiply 3 by 0.56. And then you can find your answer
Hope that this helped to some extent!