Determine the unit price to the nearest tenth of a cent, and then determine the better buy. option a: 12 eggs for $2: 30 or option b: 18 eggs for $3.25

Since the option B has the lower unit price, it is the better buy.

Step-by-step explanation:

The better buy is the one with the lowest unit price.

For each of the Options, we can find the unit price by a rule of three problem.

Rule of three problem

In a rule of three problem, the first step is identifying the measures and how they are related, if their relationship is direct of inverse.

When the relationship between the measures is direct, as the value of one measure increases, the value of the other measure is going to increase too. In this case, the rule of three is a cross multiplication.

When the relationship between the measures is inverse, as the value of one measure increases, the value of the other measure will decrease. In this case, the rule of three is a line multiplication.

In this problem, the measures are:

- The number of units

- The total price

As the number of units increases, so will the total price, which means that the relationship between the measures is direct and we have the following rule of three:

Option A:

12 units - $2.30

1 unit - $x

12x = 2.30

x = $0.20.

In option A, the unit price is $0.20

Option B

18 units - $3.25

1 unit - $x

18x = 3.25

x = $0.18.

In option B, the unit price is $0.18.

Since the option B has the lower unit price, it is the better buy.