Let the cost of each pencil be ₹ x and the cost of each pen be ₹ y.
By problem,
6 pencils and 4 notebooks together cost ₹90.
∴ 6x.+ 4y = 90 ……………. (1)
8 pencils and 3 notebooks together cost, ₹85.
∴ 8x + 3y = 85 ………….(2)
By solving the equations (1) and (2)
6x + 4y = 90 ⇒ 3(6x + 4y) = 90 x 3
⇒ 18x + 12y = 270
8x + 3y = 85 ⇒ 4(8x + 3y) = 85 x 4
⇒ 32x + 12y = 340
x = 5
From (2) ⇒ 8(5) + 3y = 85
⇒ 3y = 85 – 40 = ₹ 45
∴ y = ₹15
∴ Cost of each pencil be = x = ₹ 5
Cost of each pen be = y = ₹ 15
