Question

An elevator can lift up to 450 kg. 10 boxes weigh 13.75 kg each, and a number of additional boxes weigh 15.5 kg each. If 10 boxes are put on the elevator, how many additional boxes can be lifted in the same load?

Answer 1

20 boxes because 13.75 x 10=137.5
450-137.5=312.5
312.5/15.5=20.16
boxes=20