Question

Ten granola bars and 12 bottles of water cost $23. Five granola bars and four bottles of water cost $10. How much do one granola bar and one bottle of water cost?

Answer 1

The cost of one granola bar is
`\$1.4`

The cost of one bottle of water is
`\$0.75`

Explanation:

Let

x------> the cost of one granola bar

y-----> the cost of one bottle of water

we know that

`10x+12y=23` -----> equation A

`5x+4y=10` -----> equation B

using a graphing tool

Solve the system of equations

Remember that

The solution of the system of equations is equal to the intersection point both graphs

The intersection point is
`(1.4,0.75)`

see the attached figure

therefore

The cost of one granola bar is
`\$1.4`

The cost of one bottle of water is
`\$0.75`