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

For 136 copies of books require a shelf of length = 3.4 m
For 5.1 m shelf, let books be required = x
Therefore :
$\begin{array}{ccc}\text{Length of shelf}& 3.4m& 5.1m\\ \text{Number of books}& 136& x\end{array}$
$\therefore \frac{3.4}{136}=\frac{5.1}{x}\Rightarrow 3.4\times x=5.1\times 136\Rightarrow x=\frac{5.1\times 136}{3.4}=\frac{51\times 136\times 10}{10\times 34}=3\times 68=204$
$\therefore$ Required books = 204