Question

Winnie is buying dog food for her dog. She needs 10 pounds of food each week, but has room to store any extra food that she purchases.The food comes in 4 different sizes as given below: 4.2 pounds for $4.99 8.5 pounds for $9.27 12 pounds for $11.04 20 pounds for $18.99 Winnie is trying to be a smart shopper and get the best deal on the dog food. Which size bag of dog food should Winnie buy?

Answer 1

The correct size Winnie should by for the dog food is the one with 20 pounds. She can save a few dollars per week. She can store the extra 10 pounds for the next week. The amount of dollars she can save is around 2 dollars.

Answer 2

Let's count how expensive is one pound of dog food for all size bags:

1. For 4.2 pounds bag that costs $4.99:

$\dfrac{\ 4.99}{4.2}\approx \ 1.18809$.

2. For 8.5 pounds bag that costs $9.27:

$\dfrac{\ 9.27}{8.5}\approx \ 1.09058$.

3. For 12 pounds bag that costs $11.04:

$\dfrac{\ 11.04}{12}=\ 0.92$.

4. For 20 pounds bag that costs $18.99:

$\dfrac{\ 18.99}{20}=\ 0.9495$.

As you can see the most cheapest dog food will be buying 12 pounds bag of dog food.