Answer: A statement that is true is the package of 8 count AA batteries cost a cent more than the package of 20 count AA batteries.
Calculation: We are trying to find the unit rate: To identify it, we can start off initially by acknowledging that an 8 count package costs $6.40. Dividing this by 8 will give us our unit rate for the cost of one AA battery.
$6.40 / 8 batteries = $0.80 per battery
In a package of 8 count batteries, each battery costs $0.80.
We can apply the same process for the unit rate of a package of 20 count batteries. This would look like:
$15.80 / 20 batteries = $0.79 per battery
In a package of 20 batteries, each battery is $0.79.
Explanation: Seeing both of the unit rates, we know that $0.79 is less than $0.80. Because of this, it costs a cent more to get a single battery from an 8 count set of batteries than it would to get a singular battery from a 20 count set of batteries.
Final answer: It costs one more cent per battery for an 8 count battery than a 20 count battery. The statement about the unit prices that is true is the 20-count batteries have a lower price than the 8-count batteries.
Missing answer choices are listed in the image provided. D is the correct answer.