Posted by Matthew on .
A petroleum company has two different sources of crude oil. The first source provides crude oil that is 35% hydrocarbons, and the second one provides crude oil that is 60% hydrocarbons. In order to obtain 120 gallons of crude oil that is 55% hydrocarbons, how many gallons of crude oil must be used from each of the two sources?

Algebra 
Steve,
work with the amount of hydrocarbons present in each part:
.35x + .6(120x) = .55*120
x = 24
so, 24 gals of 35%, and 96 gals of 60% 
Algebra 
sheena,
25,8

Algebra 
david,
you left the most garbage explanation I may have seen in my entire life. Save your hands, and don't post unless its worth reading.