# Yahya works at Target Pumpkin erasers cost $.60 each and ghost erasers cost $.40 each. He sold a total of 350 pumpkin and ghost erasers for $170.00. How many pumpkin erasers did Yahya sell?

##### 3 Answers

#### Explanation:

let

150 pumpkin erasers

#### Explanation:

We can create a system of equations to represent this situation.

Pumpkin erasers cost

He sold 350 pumpkin and ghost erasers, so the number of ghost erasers plus the number of pumpkin erasers must equal 350.

When solving a system of equations, the goal is to **eliminate variables** by adding the two equations together. Two of the same variables can only cancel out if they have the same coefficient but opposite signs (for example, 2x and -2x).

Let's multiply the second equation by

Now add the equations together:

Divide both sides by

If

Hope this helps!

A very different approach just for the hell of it. The explanations takes a lot longer than the actual maths.

count of $0.6 rubbers is 150

count of $0.4 rubbers is 200

#### Explanation:

This does use the principles used by the other contributors but just looks different.

Let the count of $0.6 erasers be

Let the count of $0.4 erasers be

Let the target count of

Then no matter how many

So the blend can be anything:

from

to

Cost at condition 1

Cost at condition 2

Target value of sale

So we need to blend the two sale figures in a proportion that gives $170.

The slope of part is the same as the slope of all of it.

Thus we have:

count of $0.6 rubbers is 150

count of $0.4 rubbers is