Question

John is comparing the prices of two bags of the

same cereal. He notices that the larger bag holds 10 more ounces and
costs $1.50 more. How can he use the unit price of the smaller bag to
decide the better buy? Explain.

Answer 1

So, its better to buy larger bag

Step By Step Explanation:

Let

Smaller bag hold = x ounces

Price of x ounce in smaller bag = $ y

Price of 1 ounce in smaller bag =
`(y)/(x)` ....(1

Larger bag will hold = x + 10 ounces

Price of x+10 ounces in larger bag = y + 1.5

Price of 1 ounce in larger bag =
`(y + 1.5)/(x + 10)` ...(2

Now equation 1 tells that 1 ounce in smaller costs
`(y)/(x)`, and equation 2 tells in ounce in larger bag costs
`(y + 1.5)/(x + 10)` .

Now as we can see, we can get equation 2 from equation 1 by increasing numerator by 1.5 and denominator by 10. In this case denominator has increased more than numerator so the value of overall fraction
`(y + 1.5)/(x + 10)` would be less than
`(y)/(x)` . It means our larger bag has less price per ounce.

So, its better to buy larger bag