We are asked to find how much we save per tire if we purchase the manager's special. Let's start by summarizing all the information from the exercise using a table.
Offer
Number of Tires
Price
Regular
2
$216
Special
4
$380
We will find the unit price for each offer. Let's start with the regular offer. In this offer, 2 tires cost $ 216. We can write a rate to show this situation.
$ 216/2tiresRecall that a unit rate is a rate that has been reduced to have a denominator of 1 unit. In this case, the unit rate is the price per tire. Let's find the unit rate! To keep things simple, we will ignore the units.
We found the unit rate for the regular cost of tires!
$ 216/2tires ≈ $108/1tire
As we can see, in the regular offer, we pay $108 per tire. We can find the unit rate for the special offer by following a similar process.
Offer
Number of Tires
Price
Rate
Unit Rate
Regular
2
$216
$ 216/2tires
$ 216 ÷ 2/2tires ÷ 2 = $ 108/1tire
Special
4
$380
$ 380/4tires
$ 380 ÷ 4/4tire ÷ 4 = $ 95/1tire
Remember, the unit rate is the price per tire. Let's simplify our table a bit.
Offer
Unit Rate
Unit Price
Regular
$ 108/1tire
$ 108 per tire
Special
$ 95/1tire
$ 95 per tire
Now we can finally calculate how much we save if we purchase the manager's special. To do so, we will subtract the unit prices.
$ 108 - $ 95= $ 13
If we purchase the manager's special, we save $13 per tire!
