## Answers

take the cost of one pencil as x and cost of one pen as y

therefore 5x + 7y = 50

And 7x + 5y = 46 -----------------------------------------(1)

5x + 7y =50

7y=50 - 5x

y= (50 - 5x) / 7 ---------------------------------------------------(2)

Putting value for y from (2) to (1)

7x + 5*(50 - 5x)/7 =46

7x + (250 -25x) / 7 =46

49x + 250 - 25x = 46 * 7

24x= 72

x=3

y = (50-5*3)/7

y=35/7

y=5

Price of one pen = 5

Price of one pencil = 3

take cost of each pen is RS Y

given 5 pencils and 7 pens together cost RS.50

5X+7Y=50--eq1

and also given 7 pencils and 5 pens together cost RS.46

7X+5Y=46--eq2

by solving eq1 and eq2 we get X=3and Y=5

so,the cost of 1 pencil is RS 3

and the cost of 1 pen is RS 5