0 5 pencils and 7 pens together cost t 50, whereas 7 pencils and 5 pen

1.	0 5 pencils and 7 pens together cost t 50, whereas 7 pencils and 5 pens togethercost 46. Find the cost of one pencil and that of one pen.
Answer» Let the cost of pencil be x and the cost of the pen be y 5x + 7y = 50 . . . . . (1)7x + 5y = 46 . . . . . (2) (1) × 7 35x + 49y = 350 . . . . . (3) (2) × 5 35x + 25y = 230 . . . . . (4) (3) - (4) 24y = 120 y = 5 substituting in (2) we get x = 3 Therefore, Cost of pencil = ₹3Cost of pen = ₹5

0 5 pencils and 7 pens together cost t 50, whereas 7 pencils and 5 pens togethercost 46. Find the cost of one pencil and that of one pen.

Answer»

Let the cost of pencil be x and the cost of the pen be y

5x + 7y = 50 . . . . . (1)7x + 5y = 46 . . . . . (2)

(1) × 7

35x + 49y = 350 . . . . . (3)

(2) × 5

35x + 25y = 230 . . . . . (4)

(3) - (4)

24y = 120 y = 5

substituting in (2) we get

x = 3

Therefore, Cost of pencil = ₹3Cost of pen = ₹5