Test Index

Xavier Aptitude Test 2012 Paper

© examsnet.com

Question : 73 of 85

Marks: +1, -0

Ram prepares solutions of alcohol in water according to customers' needs. This morning Ram has prepared 27 litres of a 12% alcohol solution and kept it ready in a 27 litre delivery container to be shipped to the customer. Just before delivery, he finds out that the customer had asked for 27 litres of 21% alcohol solution. To prepare what the customer wants, Ram replaces a portion of 12% solution by 39% solution. How many litres of 12% solution are replaced?

5
9
10
12
15

Solution:

(b) Let Ram replaces

x

litres of

12\%

sol. with

39\%

solution.Now, quality of

12\%

sol. in

27

litre

= \frac{27 \times 12}{100}

\therefore

After replacing we have volume of

12\%

sol.

= \left( \frac{27 \times 12}{100} - \frac{12 x}{100} + \frac{39 x}{100} \right)

= \frac{324+27 x}{100}

This will be equal to

27

litre of

21

\%

sol.

\therefore \frac{324+27 x}{100} = \frac{21 \times 27}{100}

\therefore x = \frac{567-324}{27} = \frac{243}{27} = 9

Hence option (b)

© examsnet.com

Go to Question:

Prev Question

Next Question