Math question

Question

A box containing 30 identical books has a mass of 8.6kg. The same box containing 50 of these books has a mass of 13.1kg. What is the mass of each book? Can you show step by step on how to solve as well?

Answer 1

M = mass of 1 book in kg

m = mass of the empty box in kg

 

m + 30M = 8.6

m + 50M = 13.1

 

Subtract top equation from bottom equation and get

 

20M = 4.5

 

M = 4.5/20 kg = 0.225 kg