Question

a pencil costs $0.25 more than an eraser. if the cost of 8 pencils is $6.80, what is the cost of one eraser? how do i do this problem?

Answer 1

Hi there! The price of one eraser is $0.60

Let the price of an eraser be represented by x.
The price of a pencil is x + 0.25

Now we can set up (and solve) an equation.
8 (x + 0.25) = 6.80

Work out the parenthesis
8x + 2 = 6.80

Subtract 2.
8x = 4.80

Divide by 8
x = 4.80 / 8 = 0.60

Therefore, the price of one eraser is $0.60

Answer 2

You are given a relationship between the cost of a pencil and the cost of an eraser.
You are given sufficient information to find the cost of a pencil. Once you have done that, find the cost of the eraser using the given relationship.

8*(pencil cost) = $6.80
pencil cost = $6.80/8 = $0.85

pencil cost = $0.25 + eraser cost
pencil cost - $0.25 = eraser cost
$0.85 -0.25 = eraser cost = $0.60