Question

A shopkeeper earns a profit of $1Rs$ by selling one pen and incurs a loss of $40paise$ per pencil while selling pencils of her old stock.

In the month she earns neither profit nor loss. If she sold $70pens$, how many pencils did she sell?

Answer 1

Given us, A shopkeeper earns a profit $1Rs$ by selling one pen and a loss $40paise$ per pencil while selling pencils of her old stock.

So, As in a month she earns neither profit nor loss i.e $0$

Number of pens she sold= $70pens$

Let the number of pencils be $x$

Now, According to the question

$$\begin{gathered} 70\times 1-x\times \frac{40}{100}=0\left[\because 1paise=\frac{1}{100}Rs\right] \\ \Rightarrow 70-0.4x=0 \\ \Rightarrow 0.4x=70 \\ \Rightarrow x=\frac{70}{0.4} \\ \Rightarrow x=\frac{700}{4} \\ \Rightarrow x=175 \end{gathered}$$

Hence total number of pencil she sold are $175$