Question 133718: How many liters of pure water (o% salt) must be added to 5 liters of an 85% salt solution to dilute it so a 68% salt solution? Answer by ptaylor(2198) (Show Source):
You can put this solution on YOUR website! Let x=amount of pure water needed
Now we know that the amount of pure salt in the water (0) plus the amount of pure salt in the 5 liters (0.85*5) has to equal the amount of pure salt in the final mixture 0.68(5+x). So our equation to solve is:
0.85*5=0.68(5+x) simplify
4.25=3.4+0.68x subtract 3.4 from each side
4.25-3.4=3.4-3.4+0.68x collect like terms
0.85=0.68x divide both sides by 0.68
x=1.25 liters---------------------------Amount of pure water needed
CK
0.85*5=0.68*6.25
4.25=4.25
