Fifteen full crates of walnuts weigh 525 pounds, whereas an empty crate weighs 10 pounds. How much do the walnuts alone weigh

Question

 I need this question answered.. Also if you could explain how?

Answer 1

Since 1 empty crate weighs 10 lb., 15 empty crates weigh 150 lb. so the weight of the crates w walnuts minus the weight of the empty crates is the weight of the walnuts alone. 525-150=375 lb.