SOLUTION: how many gallons of a 90% antifreeze solution must be mixed with 90 gallons of 15% antifreeze to get a mixture that is 80% antifreeze?

Algebra.Com
Question 437599: how many gallons of a 90% antifreeze solution must be mixed with 90 gallons of 15% antifreeze to get a mixture that is 80% antifreeze?
Answer by mananth(16946)   (Show Source): You can put this solution on YOUR website!
------ Percent ---------------- quantity
Antifreeze 15 ----------------90
Antifreeze 90 ----------------x
Total 80 ---------------- 90 + x

15*90+90*x=80(90+x)
1350+90x=7200+80x
90x-80x =7200-1350
10x=5850
/10
x=585 gallons 90 % Antifreeze

RELATED QUESTIONS

how many gallons of a 50% antifreeze solution must be mixed with 90 gallons of 15%... (answered by Marth)
How many gallons of a 90% antifreeze solution must be mixed with 60% gallons of 15%... (answered by jorel1380)
how many gallons of a 90 antifreeze solution must be mixed with 100 gallons of 25... (answered by stanbon)
how many gallons of 90% antifreeze solution must be mixed with 90 gallons of 30%... (answered by josmiceli)
How many gallons of 80% antifreeze solution must be mixed with 90 gallons of 15%... (answered by lwsshak3)
how many gallons of 90 percent antifreeze solution must be mixed with 100 gallons of 10... (answered by josmiceli)
how many gallons of a 90% antifreeze solution must be mixed with 60 gallons of 10%... (answered by stanbon)
how many gallons of a 60% antifreeze solution must be mixed with 90 gallons of 30%... (answered by stanbon)
how many gallons of a 90% antifreeze solution must be mixed with 60 gallons of 30%... (answered by stanbon)