Question

3pencils and 2pens together cost rs.17, where as 2pencils and 3pens together cost rs.18, find the cost of one pencil and that of one pen​

Answer 1

Answer:

let cost of a pencil be x

and cost of a pen be y

this gives us:-

3x+2y=17

and 2x+3y=18

multiply first equation by 2 and second equation by 3.

=6x+4y=34

6x+9y=54

subtract second equation from first equation:-

6x+4y=34

6x+9y=54

- - -

this gives us

-5y=-20

y=-20/-5

y=4

put this in equation 1

=> 3x+2y=17

3x+2(4)=17

3x+8=17

3x=17-8

3x=9

x=9/3

x=3

hence the cost of one pencil is RS 3 and cost of a pen is RS 4