Question

5 pencils and 3 pens costs £11. 4 pencils and 6 pens costs £16. Find the cost of a pencil. Find the cost of a pen.

Answer 1

Answer:

5x+3y=11............1

4x+6y=16...........2

multiply eqn 1 by 2

10x+6y=22

subtract eqn 2 from eqn 1

6x=6

x=1

putting the value of x in eqn 1

5×1+3y=11

3y=11_5

3y=6

y=2

so the cost of one pencil is 1 and the cost of one pen is 2