Question

At McDonald's, 4 burgers and 3 containers of fries cost $16.40. Your finger rubbed off part of your receipt but you could see that each burger was $3.20.

What is the cost of a container of fries at McDonald's? Show your work. Label your answer. USE SUBSTITUTION

Answer 1

The price of 1 container of fries is $1.20

Explanation:

Let the price of 1 burger = B

Let the price of 1 container of fries = F

We know from the question that:

`4B + 3F = 16.40`

We also know that:

`B = $3.20`

So we can substitute B into the first equation to get:

`4(3.20) + 3F = 16.40\\12.80 + 3F=16.40\\3F=16.40-12.80\\3F=3.60\\F=(3.60)/(3)\\ F=1.20`

So the price of 1 container of fries is $1.20