Question

5 pencil and 7 pens together cost rupees 50, 7 pencil and 5pens together are rupees 46 Find the cost of 1pencil and 1 pen

Answer 1

let the cost of pencil is x rupees

cost of pen = y rupees

A.T.Q.

$5x + 7y = 50 \\ \\ 7x + 5y = 46$
multiply eq 1 by 7 and 2 by 5 and subtract both

$35x + 49y = 350 \\ 35x + 25y =23 0 \\ - \: \: \: \: \: \: - \: \: \: \: \: \: \: \: \: - \\ \\ 24y = 120 \\ \\ y = \frac{120}{24} \\ \\ y = 5$

$5x + 7 \times 5 = 50 \\ \\ 5x = 50 - 35 \\ \\ 5x = 15 \\ \\ x = 3$
cost of one pencil is 3 rupees

cost of one pen 5 rupees