Question

in 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 -length of 5.1 meters?

Answer 1

Answer:

204 books

Step-by-step explanation:

First, you can write this as a proportion $\frac{136}{3.4} =\frac{x}{5.1}$ with x as the number of books that needs to occupy 5.1 meters. Cross multiplying would get 5.1(136)=3.4x. If you expand the left side, you get 693.6. Dividing both sides by 3.4 would get you your answer, as x= 204.

Answer 2

Let x be the number of copies that would occupy a self-length of 5.1m.

Number of copies 136 x

Length the self ( in m ) 3.4 5.1

Since, the number of copies and the length of the shelf are in direct variation.

$∴ \frac{136}{x} = \frac{3.4}{5.1}$

$⇒136 \times 5.1=x \times 3.4$

$⇒x= \frac{136 \times 5.1}{3.4}$

$⇒x=204$

∴ 204 copies will occupy a shelf of length 5.1m.