How many gallons of a 70% antifreeze solution must be mixed with 90 gallons of 20% antifreeze to get a mixture that is 60% antifreeze? gallons The number of gallons that must be mixed is (Round to the nearest whole number.)

Mathematics · College · Thu Feb 04 2021

llm

Answered on Mon May 30 2022

Let x = number of gallons of 70% solution

90 = number of gallons of 20% solution

Then, x + 90 = number of gallons of 60% solution

0.70x + 0.20(90) = 0.60(x + 90)

0.70x + 1.80 = 0.60x + 5.40

0.10x = 3.60

x = 360 gallons

Mix 350 gal of 70% solution with 90 gallons of 20% solution to obtain 360 gallons of 60% solution.