Question

please write full explanation!!!
17.A shopkeeper earns a profit of ₹ 2 by selling one pen and incurs a loss of
50 paise per pencil while selling pencils of his old stock.
i) In a particular month he incurs a profit of ₹10. In this period, he sold
30 pens. How many pencils did he sell in this period?
ii) In the next month, he earns neither profit nor loss. If he sold 60 pens,
how many pencils did he sell?

Answer 1

Answer:

By selling a pen gain is Rs.2

and by selling a pencils, he loses 50 paise

and an eraser, he loses 15 paise

On one day, he gain =Rs.10

On that day he sold 10 pens and pencils and erasers in the ratio of 7:10

On ten pens, his gain =10×2=Rs.20

loss on pencils and erasers =Rs.20−Rs.10=Rs.10=1000 paise

Ratio in pencil and eraser =7:10

Let number of pencils =7x, then eraser =10x

7x×50+10x×15=1000

⇒350x+150x=1000

⇒500x=1000

⇒x=2

Numbe rof penciles =7×2=14

and number of erasers =10×2=20