Final answer:
After calculating the cost per present for both online and in-store purchases, it is determined that the in-store purchase offers a better deal at $1.67 per present compared to the online purchase, which costs $2.33 per present.
Step-by-step explanation:
To determine which place offered the better deal for the presents Sally bought, we need to calculate the cost per present at each location. Sally bought 18 presents online for $42 and 12 presents in-store for $20.
- Online purchase: $42 ÷ 18 presents = $2.33 per present
- In-store purchase: $20 ÷ 12 presents = $1.67 per present
The in-store purchase has a lower cost per present than the online purchase. Therefore, the answer is B) In-store.