Answer :
One way to find out which bag is better to buy is to find out how much is 1 pound worth in both situations. So we have to divide the prices of 8 pound bag by 8 and 4 pound bag by 4:
$7.40 ÷ 8 = $0.925 per pound
$5.38 ÷ 4 = $1.345 per pound
1.345 > 0.925, so it's better to buy 8-pound bag
$7.40 ÷ 8 = $0.925 per pound
$5.38 ÷ 4 = $1.345 per pound
1.345 > 0.925, so it's better to buy 8-pound bag
Find how much cost one pound of dog food.
- If Abby can buy an 8 pound bag of dog food for $7.40, then one pound costs $7.40:8=$0.925;
- If Abby can buy a 4 pound bag of dog food for $5.38, then one pound costs $5.38:4=$1.345.
As you can see $0.925<$1.345, then the better buy is an 8 pound bag of dog food for $7.40, because the price for one pound is less.
