Question

A shopkeeper gains ₹ 1 on each sharpener and loses 40 paisa on each eraser. He sells 90 sharpeners and some erasers losing ₹ 10 in all. How many erasers does he sell?

Answer 1

   Answer:

   $\boxed{\text{200 erasers}}$

   Step-by-step explanation:

   Let the number of erasers sold be $x$

⇒ According to the question shopkeeper gains ₹ $1$ on each sharpener and

   loses $40$ paisa on each eraser. He sells $90$ sharpeners and some erasers

   losing ₹ $10$ in all.

⇒ After converting ₹ $1$ into paisa we get

   $90(100) - x(40) = 1000$

⇒ $9000 - 40x = 1000$

⇒ $-40x = 1000-9000$

⇒ $-40x = -8000$

⇒ $x = \frac{-8000}{-40}$

⇒ $x = 200$

∴ The shopkeeper sells $200$ erasers