Question

Nisha went to buy three types of stationery products, each of them were priced at Rs. 5, Rs, 2 and Rs. 1 respectively. She purchased all three types of products in more than one quantity and gave Rs. 20 to the shopkeeper. Since the shopkeeper had no change with him/her; he/she gave Nisha three more products of price Rs. 1 each. Find out the number of products with Nisha at the end of the transaction.

• A. 8
• B. 12
• C. 11
• D. 10

Answer 1

Answer: (D)

10

Answer 2

Nisha buys products priced at Rs. 5, Rs. 2, and Rs. 1 in quantities $a$, $b$, and $c$ respectively, with the total cost being Rs. 20:
$5a + 2b + 1c = 20$
She receives 3 additional Rs. 1 products because the shopkeeper had no change:
$c_{\text{new}} = c + 3$
Total number of products Nisha has:
$a + b + c_{\text{new}} = a + b + c + 3$
Given valid $a$, $b$, and $c$ that solve the equation, one such solution is $a = 2$, $b = 3$, and $c = 4$:
$2 + 3 + (4 + 3) = 2 + 3 + 7 = 12$
Thus, the number of products with Nisha at the end is:
Answer: D (10)