Find the cost per ounce of each brand's dish soap and compare the results.
C
Practice makes perfect
We are given the following table.
Dish Soap Prices
Brand
Price
Lots of Suds
$0.98 for 8 ounces
Bright Wash
$1.29 for 12 ounces
Spotless Soap
$3.14 for 30 ounces
Lemon Bright
$3.45 for 32 ounces
We want to determine which brand costs the least per ounce. We can do this by finding the cost per ounce of each brand's dish soap. Let's start with Lots of Suds. We know that 8 ounces of this brand's dish soap costs $ 0.98. We can write a rate to show this situation.
$ 0.98/8ouncesRecall that a unit rate is a rate that has been reduced to a denominator of 1 unit. In this case, the unit rate is the cost per ounce of dish soap. Let's find the unit rate! We can ignore the units for now to keep things simple.
We found the unit rate!
$ 0.98/8ounces ≈ $ 0.12/1ounce
As we can see, dish soap from Lots of Suds costs about $0.12 per ounce. We can find the unit rate for the other brands by following the same steps.
Brand
Price
Rate
Unit Rate
Lots of Suds
$0.98 for 8 ounces
$ 0.98/8ounces
$ 0.98 ÷ 8/8ounces ÷ 8 ≈ $ 0.12/1ounce
Bright Wash
$1.29 for 12 ounces
$ 1.29/12ounces
$ 1.29 ÷ 12/12ounces ÷ 12 ≈ $ 0.11/1ounce
Spotless Soap
$3.14 for 30 ounces
$ 3.14/30ounces
$ 3.14 ÷ 30/30ounces ÷ 30 ≈ $ 0.10/1ounce
Lemon Bright
$3.45 for 32 ounces
$ 3.45/32ounces
$ 3.45 ÷ 32/32ounces ÷ 32 ≈ $ 0.11/1ounce
Remember, the unit rate is the price per ounce of dish soap.
Brand
Unit Rate
Unit Price
Lots of Suds
≈ $ 0.12/1ounce
≈ $ 0.12 per ounce
Bright Wash
≈ $ 0.11/1ounce
≈ $ 0.11 per ounce
Spotless Soap
≈ $ 0.10/1ounce
≈ $ 0.10 per ounce
Lemon Bright
≈ $ 0.11/1ounce
≈ $ 0.11 per ounce
We can see that Spotless Soap costs the least per ounce. This means that C is the correct answer!
