part A + B if you subtract 3,000 - 900 ( piano ) = 2,100 then if you keep subtracting 300 ( 1 crate of electronics ) soon you will get down to 0 then you can count how many times you subtracted 300 which in my answer 6 crates will fit with the piano part A ( 3,000 - 900) - 300 until 0 because it's 6 crates it said it was just under 3,000 pounds not on the exact weight.