A chemical company makes two brands of antifreeze.

Question

A chemical company makes two brands of antifreeze. The first brand is 55% pure antifreeze, and the second brand is 80% pure antifreeze. In order to obtain 140 gallons of a mixture that contains 60% pure antifreeze, how many gallons of each brand of antifreeze must be used

Answer 1

x = number of gallons of the 55% brand

140 - x = number of gallons of the 80% brand

Set this up as a weighted combination of mixtures:

55x + 80(140 - x) = 60(140)

Can you solve for x and finish from here?