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.
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)
