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A scientist needs 270 milliliters of a 20% acid solution for an experiment. The lab has available a 25% and a 10% solution. How many milliliters of the 25% solution and how many milliliters of the 10% solution should the scientist mix to make the 20% solution?

User Dr Nisha Arora
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1 Answer

18 votes
18 votes

Given:

A scientist has 5% and a 10% acid solution in his lab.

He needs 270 milliliters of a 20% acid solution.

To find the amount of 25% solution and how many milliliters of the 10% solution should the scientist mix to make the 20% solution:

Here,

The dearer percentage is 25%.

The cheaper percentage is 10%.

The mean percentage is 20%.

Using the mixture and allegation method,

The ratio of the litters of cheaper (10% solution) to dearer value (25% solution) is,


\begin{gathered} (\text{Dearer value-mean): (Mean-Ch}eaper\text{ value)} \\ (25-20)\colon(20-10) \\ 5\colon10 \\ 1\colon2 \end{gathered}

So, the number of liters to be taken from 10% solution is,


(1)/(3)*270=90\text{ liters}

So, the number of liters to be taken from 25% solution is,


(2)/(3)*270=180\text{ liters}

Hence, the answer is

User Sdooo
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