SOLUTION: How many liters of 30% alcohol solution must be mixed with 70 liters of 70% solution to get a 50% solution?
Algebra.Com
Question 178448: How many liters of 30% alcohol solution must be mixed with 70 liters of 70% solution to get a 50% solution?
Answer by Mathtut(3670) (Show Source): You can put this solution on YOUR website!
let x and y be the 30% and 70% solutions respectively
:
x+y=70......eq 1
.3x+.7y=.5(70)...eq 2
:
take eq 1 and rewrite it to y=70-x and plug it into eq 2
:
.3x+.7(70-x)=.5(70)
:
.3x+49-.7x=35
:
-.4x=-14
:
liters of 30% solution
:
liters of 70% solution
:
we really could have come up with this by common sense. 50% is half way between
30% and 70% so to have equal portions makes total sense
RELATED QUESTIONS
How many liters of a 60% alcohol solution must be mixed with 50 liters of a 90% solution... (answered by stanbon)
[ how many liters of a 40% alcohol solution must be mixed with 60 liters of a 70%... (answered by TimothyLamb)
How many liters of a 50% alcohol solution must be mixed with 80 liters if a 90% solution (answered by stanbon)
How many liters of a 30% alcohol solution must be mixed with 20 liters of a 70% solution... (answered by Maths68)
how many liters of a 10 alcohol solution must be mixed with 80 liters of a 70% solution... (answered by nerdybill)
How many liters of a 70% alcohol solution must be mixed with 30 liters of a 15% alcohol... (answered by Earlsdon)
how many liters of a 40% alcohol solution must be mixed 60 liters of a 70% solution to... (answered by stanbon)
How many liters of a 20% alcohol solution must be mixed with 60 L of a 70% solution to... (answered by stanbon)
How many liters of a 20% alcohol solution must be mixed with 60 liters of a 90% solution... (answered by josmiceli)