SOLUTION: How many gallons of a 90 ​% antifreeze solution must be mixed with 100 gallons of 25 ​% antifreeze to get a mixture that is 80 ​% ​antifreeze?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: How many gallons of a 90 ​% antifreeze solution must be mixed with 100 gallons of 25 ​% antifreeze to get a mixture that is 80 ​% ​antifreeze?       Log On


   

Question 1047973: How many gallons of a 90
​%
antifreeze solution must be mixed with 100

gallons of 25
​%
antifreeze to get a mixture that is 80
​%
​antifreeze? Use the​ six-step method.
Found 2 solutions by josgarithmetic, addingup:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
What six-step method?

v, how much antifreeze 90% to add

%28100%2A25%2Bv%2A90%29%2F%28v%2B100%29=80

Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be the amount of 90% solution:
0.90x+0.25(100) = 0.80(100+x)
0.90x+25 = 80+0.80x
0.10x = 55
x = 550 gallon