Answer:
Therefore, mom had the better unit rate, as she paid less per book than dad did.
Explanation:
To determine who had the better unit rate, we need to divide the cost by the number of books for each parent.
For mom, the unit rate would be:
$19.85 ÷ 8 books = $2.48 per book
For dad, the unit rate would be:
$15.00 ÷ 6 books = $2.50 per book
Therefore, mom had the better unit rate, as she paid less per book than dad did.
To further explain, the unit rate is the cost per unit of measure, in this case, the cost per book. When comparing two different unit rates, the one with the lower cost per unit is the better value. In this scenario, mom paid $0.02 less per book than dad did, making her unit rate better.