At the grocery store pretzels are 2.40 for a 12-ounce bag and 18.00 for a 60 ounce container. Maria wants to get 60 ounce for a party she is hosting. How many will Maria save per ounce by making the less expensive selection?

Answer 1

The 60-ounce container costs 18 dollars or 18/60= <<18/60=.3>>.3 dollar per ounce.
To see how much Maria saves she needs to calculate how much money 3 dollars for 12-ounce amounts to per ounce.
First Maria needs to express 2.40 dollars in terms of ounces, so the price is .20 an ounce.
Next, she needs to find out how many units of .20 ounces make up 1 whole ounce. To do this she divides 1 by .20, finding that .20 ounces make up 5 times as much.
Finally she multiplies .20 times 5, finding that a 12 end up costing four times as much per ounce as a 60, so the Maria saves .3-.2=.1 dollar per ounce by buying the 60 sized container. Answer: \boxed{.1}.