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A scientist mixes water (containing no salt) with a solution that contains 35% salt. She wants to obtain 245 ounces of a mixture that is 15% salt. How many ounces of water and how many ounces of the 35% salt solution should she use?

Respuesta :

Poltergeist

Answer:

140 ounces of water and 105 ounces of 35% salt solution.

Explanation:

Let [tex]x[/tex] be the ounces of water that need to be added and [tex]y[/tex] be the ounces of 35% solution that need to to be added.

We know that the total of ounces of water and of 35% solution must be 245 ounces:

[tex]x+y=245[/tex]

35% of  [tex]x[/tex] is the salt, and since no salt is added with addition of [tex]y[/tex]  liters of water, this must be equal to the amount of salt in the final 15% solution:

[tex]0.35x=0.15*245[/tex]

we solve for  [tex]x[/tex] and get:

[tex]x=105[/tex]

We put this value into [tex]x+y=245[/tex] and solve for [tex]y[/tex] to get:

[tex]y=140[/tex]

Thus we have 140 ounces of water and 105 ounces of 35% solution.

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