Question

In a library 136 copies of a certain book require a shelf-length of 3.4 metre. How many copies of the same book would occupy a shelf length of 5.1 metres?

Answer 1

Let’s consider number of copies as ‘x’

Shelf-length (m)	3.4	5.1
No. of copies	136	x

3.4/136 = 5.1/x

By cross-multiplying

3.4x = 5.1(136)

3.4x = 693.6

x = 693.6/3.4

= 204

∴ Number of copies are 204.