Question

Chemical company makes two brands of antifreeze. The first brand is

60%
pure antifreeze, and the second brand is
85%
pure antifreeze. In order to obtain
140
gallons of a mixture that contains
70%
pure antifreeze, how many gallons of each brand of antifreeze must be used?

Answer 1

We have 60% and 85% antifreeze
We need 140 gallons of 70% antifreeze
x + y = 140
.60x + .85y = .70 * 140

X = 84 gallons 60%
Y = 56 gallons 85%