Question 561722: How many liters of a 10% salt solution should be added to 80 liters of a 35% salt solution to obtain a mixture that is a 30% salt solution? Answer by TutorDelphia(193) (Show Source):
You can put this solution on YOUR website! We want the amount of salt to be 30 per every 100 liters.
Our new solution is made up of 80 l of 35% salt plus an unknown amount of 10% salt.
If I multiply 80*.35 I have how much salt I currently have. If I add that to the amount of salt that I add which would be x*.10 (since its 10 of the liters I add) I get my new total salt.
If I divide by how many liters I have 80 + x (the amount of solution I'm adding I can set up a proportion that is salt/liter that looks like this:
80*.35 is 28
cross multiply
2800+10x=2400+30x
subtract 2400 from both sides
400+10x=30x
subtract 10x from both sides
400=20x
divide both sides by 20
20=x
