Question

you have a $20 bill. If you buy 24 pensa and 12 pencils, you will get $1.40 change. If you buy 12 pens and 24 pencils, you will get 4.40 change. How much does each pen and each pencil cost

Answer 1

The cost of a pen is $0.60 and the cost of a pencil is $0.35

Explanation:

Let

x-----> the cost of a pen

y----> the cost of a pencil

we know that

24x+12y=20-1.40

24x+12y=18.60 -----> equation A

12x+24y=20-4.40

12x+24y=15.60 -----> equation B

Solve the system of equations by graphing

Remember that the solution is the intersection point both graphs

The solution is the point (0.60,0.35)

see the attached figure

therefore

The cost of a pen is $0.60

The cost of a pencil is $0.35