Question

If a dozen erasers cost $₹54,$how many erasers can be bought for $₹$$99?$

Answer 1

Number of erasers and their cost will be in proportion

Let the number of erasers bought for $₹99$is $x.$

$$\begin{gathered} \Rightarrow \frac{12}{54}=\frac{x}{99} \\ \Rightarrow \frac{2}{9}=\frac{x}{99} \\ \Rightarrow 2\times 99=9\times x \\ \Rightarrow 198=9x \\ \Rightarrow x=\frac{198}{9} \\ \Rightarrow x=22. \end{gathered}$$

So, the value of $x$is $22.$