It is currently 15 Dec 2017, 04:27

# Decision(s) Day!:

CHAT Rooms | Wharton R1 | Stanford R1 | Tuck R1 | Ross R1 | Haas R1 | UCLA R1

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A 100-litre mixture of milk and water contains 36 litres of

Author Message
TAGS:

### Hide Tags

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7800

Kudos [?]: 18133 [2], given: 236

Location: Pune, India
A 100-litre mixture of milk and water contains 36 litres of [#permalink]

### Show Tags

19 Nov 2017, 20:40
2
KUDOS
Expert's post
1
This post was
BOOKMARKED
alphonsa wrote:
A 100-litre mixture of milk and water contains 36 litres of milk. 'x' litres of this mixture is removed and replaced with an equal quantum of water. If the process is repeated once, then the concentration of the milk stands reduced at 25%. What is the value of x?

A) 17.5 litres
B) 16.67 litres
C) 17.67 litres
D) 16.5 litres
E) 16 litres

Source: 4Gmat

Responding to a pm:

First check this post: https://www.veritasprep.com/blog/2012/0 ... -mixtures/

You are removing a part of the solution and adding water. When you add water, the amount of milk remains the same.

C1*V1 = C2*V2
This is repeated once more.

C2 = C1 * (V1/V2)^2

$$.25 = .36 * [\frac{(100 - x)}{100}]^2$$

$$\frac{(100 - x)}{100} = \frac{5}{6}$$

x = 100/6 = 16.67 litres
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

Kudos [?]: 18133 [2], given: 236

Manager
Status: love the club...
Joined: 24 Mar 2015
Posts: 213

Kudos [?]: 21 [0], given: 472

Re: A 100-litre mixture of milk and water contains 36 litres of [#permalink]

### Show Tags

20 Nov 2017, 15:18
VeritasPrepKarishma wrote:
alphonsa wrote:
A 100-litre mixture of milk and water contains 36 litres of milk. 'x' litres of this mixture is removed and replaced with an equal quantum of water. If the process is repeated once, then the concentration of the milk stands reduced at 25%. What is the value of x?

A) 17.5 litres
B) 16.67 litres
C) 17.67 litres
D) 16.5 litres
E) 16 litres

Source: 4Gmat

Responding to a pm:

First check this post: https://www.veritasprep.com/blog/2012/0 ... -mixtures/

You are removing a part of the solution and adding water. When you add water, the amount of milk remains the same.

C1*V1 = C2*V2
This is repeated once more.

C2 = C1 * (V1/V2)^2

$$.25 = .36 * [\frac{(100 - x)}{100}]^2$$

$$\frac{(100 - x)}{100} = \frac{5}{6}$$

x = 100/6 = 16.67 litres

many many thanks to you, mam

Kudos [?]: 21 [0], given: 472

Re: A 100-litre mixture of milk and water contains 36 litres of   [#permalink] 20 Nov 2017, 15:18

Go to page   Previous    1   2   [ 22 posts ]

Display posts from previous: Sort by