Question

A man purchased 47 stamps of 20 p and 25 p for ₹ 10. Find the number of each type of stamps.

Answer 1

Let the number of stamps of 20 p and 25 p be x and y respectively.

Then as per the question

x + y = 47   ...(i)

0.20x + 0.25y = 10

4x + 5y = 200   ...(ii)

From (i), we get

y = 47 – x

Now, substituting y = 47 – x in (ii), we have

4x + 5(47 – x) = 200

⇒ 4x – 5x + 235 = 200

⇒ x = 235 – 200

⇒ x = 35

Putting x = 35 in (i), we get

35 + y = 47

⇒ y = 47 – 35

⇒ y = 12

Hence, the number of 20 p stamps and 25 p stamps are 35 and 12 respectively.