SOLUTION: Hello I'm having trouble with tthese 2 questions can you please help me solve them the 1st one is Nancy begins with 15l of 10% salt solution. How many liters of a 5% salt solution
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Question 1123595: Hello I'm having trouble with tthese 2 questions can you please help me solve them the 1st one is Nancy begins with 15l of 10% salt solution. How many liters of a 5% salt solution should she add to it in order to obtain an 8% salt solution? Found 2 solutions by solver91311, greenestamps:Answer by solver91311(24713) (Show Source):
Here is an alternative to the traditional algebraic solution method shown by the other tutor for solving problems like this where two ingredients are being mixed.
If you understand how to use this method, it will get you to the solution to problems like this with far less work than the algebraic method.
(1) You are starting with a 10% solution and adding 5% solution; you want to end up with a mixture of 8%. As you begin adding 5% solution, the percentage of the mixture decreases from 10% towards 5%.
(2) Here is the key to this method: 8% is 2/5 of the way from 10% to 5%; that means 2/5 of the mixture must be the added 5% solution.
(3) 2/5 being the 5% solution means 3/5 is the 10% solution you started with.
(4) 2/5 and 3/5 means the ratio of the amounts of the two ingredients is 2/5:3/5, or 2:3. In other words, you need 2 parts of the added 5% salt solution to 3 parts of the original 10% salt solution.
(5) Since you started with 15 liters of the 10% salt solution, the 2:3 ratio means you need 10 liters of the 5% salt solution.
