How many gallons of a ​60% antifreeze solution must be mixed with 60 gallons of ​20% antifreeze to get a mixture that is 50​% ​antifreeze?

Question

How many gallons of a ​60% antifreeze solution must be mixed with 60 gallons of ​20% antifreeze to get a mixture that is 50​% ​antifreeze?

Answer 1

.6x + .2(60) = .5(x+60)= .5x +30

.1x = 30-12=18

x = 18/.1= 180 gallons of 60%

mixed with 60 gallons of 20%

to get 240 gallons of 50%

6-5 =1

5-2 = 3

3/1 = 3 times as much 60% needed

180/60 = 3