Question

5 PENCILS AND 7 PENS COST 50 RUPPEES WHERE AS 7 PENCILS AND 5 PENS COST 40 RUPPEES.FIND THE COST OF 1 PENCIL AND THAT OF 1 PEN.

Answer 1

Answer:

Let pencil be x

Let pen be y

=> 5x+7y=50

=> 7x+5y=46

multiply first equation by 7

=> 35x+49y = 350

multiply second equation by 5

=> 35x+25y=230

solving them we get 24y=120 which gives y is 5 rupees

substituting in second equation we get x is 3 rupees