Final answer:
By comparing the cost per ream, which is $2.80 for option A (15 reams for $42.00) and $2.85 for option B (20 reams for $57.00), it is clear that option A provides the better deal per ream of paper.
Step-by-step explanation:
To determine which is the better deal per ream of paper, we need to calculate the price per ream for each option.
For option A, which is 15 reams of paper for $42.00, we would calculate the price per ream by dividing the total cost by the number of reams:
$42.00 ÷ 15 reams = $2.80 per ream
For option B, which is 20 reams of paper for $57.00, we perform a similar calculation:
$57.00 ÷ 20 reams = $2.85 per ream
Comparing the two results, we see that option A has a lower cost per ream, making it the better deal.