Math word problem

Question

A grocery store bought ice cream for $2.80 per half gallon and stored it in two freezers. During the night, one freezer malfunctioned and ruined 12 half gallons. If the remaining ice cream is sold for $3.96 per half gallon, how many half gallons did the store buy if they made a profit of $66.16?

Answer 1

Profit = Money earned- Money spent

x= total number of gallons bought

so:

 

$66.16 = $3.96(x-12) - $2.80(x)

 

Simplifying:

66.16= 1.16x - 47.52

 

Add 47.52 to both sides

1.16x= 113.68

 

Divide both sides by 1.16

x= 98