If he only ordered 10 pies at $8.50 each, the total would be $85 +$5 delivery. That would make each pie cost $9.00 each. If he bought 12 pies the total cost would be $102. I think the better deal would be to buy 12 at $8.50 each because the cost different for 2 more pies would only be $12. The last 2 pies would only be $6 each above the cost of the 10 with delivery. My only ? is if they want you to set it up as a proportion, or decide which is the most cost efficient.
