Question

The weight of 72 books is 9 kg.

How many such books would weigh 6 kg?

Answer 1

Weight of $72$ books $=9kg$

Weight of $1$ book $=\frac{9}{72}=\frac{1}{8}kg$

Total number of books weigh $6kg$ $=\frac{6kg}{weightof1book}=\frac{6}{{\displaystyle \frac{1}{8}}}=6\times 8=48$

Hence, the number of books which weigh $6kg$ is $48$.