The cost of 21 pencils and 9 pens is ₹276, and the cost of 6 pencils and 3 pens is ₹84. The cost of 1 pencil and 1 pen is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. ₹20.
Let the cost of 1 pencil and 1 pen by x and y respectively.
According to the given question,
21x + 9y = 276
⇒ 7x + 3y = 92 ...(i)
Also, 6x + 3y = 84 ...(ii)
Subtracting equation (ii) from equation (i),
⇒ x = 8
Putting the value of x in equation (i),
⇒ 7(8) + 3y = 92
⇒ 3y = 92 - 56
⇒ y = 36/3
⇒ y = 12
Now, x + y = 12 + 8 = 20