A notebook costs ₹12 each. A pen costs ₹9 each. Tina spends ₹123 on a total of 11 pieces of these articles. How many notebooks did she purchase?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4. i.e. 8.
Let the number of notebooks purchased = x
Let the number of pens purchased = y
Cost of one notebook = Rs.12
Cost of each pen = Rs. 9
Total money spent by Tina = Rs.123
Total number of articles = 11
According to the question;
x + y = 11 --------- (1)
12x + 9 y = 123 -------------- (2)
From equation 1;
y = 11 - x
Substituting the value of y in equation 2;
12x + 9(11 - x) = 123
⇒ 12x + 99 - 9x = 123
⇒ 3x = 123 - 99
⇒ 3x = 24
⇒ x = 8
Hence, Tina purchased 8 notebooks.