Question

5 pencils and 7 pens together cost rs 50, whereas 7 pencils and 5 pens together cost rs 46. find the cost of one pencil and that of one pen. By substitution method​

Answer 1

Step-by-step explanation:

Let cost of 1 pencil= x

1 pen= y

Then,

5x+7y=50 -------(1)

And,

7x+5y=46 ------(2)

From equation 1 we get x=50-7y/5

On substituting

7(50-7y/5)+5y=46. =>. 350-49y/5+5y=46

350-49y+25y= 46 x 5

350-24y= 230

24y= 120

y=5

Substituting in eq(1)

5x+7(5)=50

5x=15

x=3

Hence

Cost of 1 pencil= ₹3

Cost of 1 pen= ₹5