Which is the better buy, 7 pounds of meat for $8.47 or 9 pounds of meat for $11.07?

Question

Please explain step by step.

Answer 1

Which is the better buy, 7 pounds of meat for $8.47 or 9 pounds of meat for $11.07?

This problem illustrates the important skill of price comparison when buying groceries.

What you want to do is express both prices as some amount per pound. The price per pound is used for comparison.....thus

price per pound.....is price/pound......$8.47/7lbs = ??/1lbs ....the ratios are equal....so 8.47/7 = ?/1

cross multiply....you have 8.47 = 7x x= 8.47/7 = 1.21 or $1.21 for 1lb or $1.21 per pound

check.....7 x $1.21 = $8.47....that checks....the first meat is $1.21 per pound

$11.07/9lb = 11.07/9 = 1.23 or $1.23 for 1lb or $1.23 per pound

check....9 x $1.23 = $11.07...that checks.....the 2nd meat is $1.23 per pound

The first meat cost less per pound than the second meat....because $1.21 < $1.23....so your "better" buy is the least expensive first meat at $1.21 per pound. Right?

Answer 2

Start by finding the "Unit Rate" for both options.

It costs $8.47 to buy 7 pounds of meat. How much does it cost to buy ONE pound of meat at this rate? Divide $8.47 by 7 pounds to get $1.21/pound. That's its Unit Rate.

It costs $11.07 to buy 9 pounds of meat. How much does it cost to buy ONE pound of meat at this rate? Divide $11.07 by 9 pounds to get $1.23/pounds. That's its Unit Rate.

Now compare the unit rates. $1.21 per pound is less than $1.23 per pound so $8.47 for 7 pounds of meat is the better buy.

Answer 3

8.47/7=1.21 per pound

11.07/9=1.23 per pound

Answer 4

Well if those prices of $8.47 and $11.07 are rates for the respective pounds of meat.

Then do the following:

For the 7 lbs at a rate of $8.47 per lb.

Multiple $8.47 by 7 lbs: $59.29 for the total price.

For the 9 lbs at a rate of $11.07 per lb.

Multiple $11.07 by 9 lbs: $99.63 for this total price.

Such that 7 lbs for $8.47 is the better deal.