You need to buy some chicken for dinner tonight. You found an ad showing that the store across town has it on sale for $3.09 a pound, which is cheaper than your usual neighborhood store

Question

You need to buy some chicken for dinner tonight. You found an ad showing that the store across town has it on sale for $3.09 a pound, which is cheaper than your usual neighborhood store, which sells it for $3.39 a pound. Is it worth the extra drive?

Information you'll need:

1. How much chicken will you be buying? 7 pounds
2. How much far are the two stores? My neighborhood store is 2.3 miles away, and takes about 8 minutes. The store across town is 8.8 miles away, and takes about 24 minutes.
3. How kind of mileage does your car get? It averages about 24 miles per gallon in the city.
4. How many gallons does your car hold? About 16 gallons
5. How much is gas? About $3.85/gallon right now.

Which store would be cheaper?

How much money would you save by going to the cheaper store?

Answer 1

If the chicken you're buying is 0.3 dollars cheaper per pound and you're buying 7 pounds, the overall savings is 0.3*7 = 2.1 dollars.

The store with the cheaper chicken is 8.8-2.3 = 6.5 miles further away. Since your car averages 24 mpg, you'll use an extra 6.5/24 = 0.27 gallons to get there. Since gas is 3.85 per gallon, you'll spend an extra 0.27*3.85 = 1.04 dollars, so you save 2.10 - 1.04 = 1.06 dollars by buying the cheaper chicken.