Question

A bookstore had 30816 exercise books which were packed in cartons. Each carton contained 24 exercise books . The mass of an empty carton was 2kg and a full carton 12kg.

1. How many cartons were there?
2. What was the total mass of the empty cartons? 
3. What was the total mass of the books alone?

Answer 1

1. How many cartons were there? 
   30816/24=1284
2. What was the total mass of the empty cartons? 
   1284 x 2=2568
3. What was the total mass of the books alone? 
   12-2=10kg
   1284 x 10=12840kg