SOLUTION: If you boil 3 gallons of 10% salt water until ther is only 2 gallons of water. What is the percent of salt when you finish? Next question is: Dilute 35 gallons of 40% acid wit

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: If you boil 3 gallons of 10% salt water until ther is only 2 gallons of water. What is the percent of salt when you finish? Next question is: Dilute 35 gallons of 40% acid wit      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 22531: If you boil 3 gallons of 10% salt water until ther is only 2 gallons of water. What is the percent of salt when you finish?
Next question is:
Dilute 35 gallons of 40% acid with 7 gallons of water. What is the amount and strength of the mixture?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
One way to do this is to "follow the water".
You started with 3 gallons that was 90%water.
You boiled off 1 gallon that was 100%water.
You ended up with 2 gallons that was "x"% water.
Equation:
0.9 (3) - 1(1) = (x)(2)
2.7 - 1 = (x)(2)
1.7/2 = x%
x = 0.850
The 2 gallons at the end is 85% water.
So it is a 15% salt water solution.
=================================================
This time we will "follow the acid"
You start with 35 gallons that is 40% acid.
You add 7 gallons that is 0% acid.
You end up with 42 gallons that is x% acid.
Equation:
0.40(35) + 0(7) = 42x
x = 14/42 = 33% acid
Cheers,
Stan H.