GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 20 Jun 2018, 04:23

### 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

# Krisp cereal is 10% sugar by weight. Brano cereal is 2% su

Author Message
TAGS:

### Hide Tags

Manager
Joined: 24 May 2010
Posts: 77
Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

23 Jun 2010, 18:34
6
00:00

Difficulty:

(N/A)

Question Stats:

83% (00:34) correct 17% (00:28) wrong based on 43 sessions

### HideShow timer Statistics

Krisp cereal is 10% sugar by weight. Brano cereal is 2% sugar by weight. If you wanted to make the mixture 4% sugar by weight what should the ratio of Krisp to Brano.
SVP
Status: Three Down.
Joined: 09 Jun 2010
Posts: 1869
Concentration: General Management, Nonprofit
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

23 Jun 2010, 19:29
2
A similar logic to what I said in the previous question can be used here.

Let us assume he takes x grams of Krisp and y grams of Brano.

So the total weight of the new mixture is (x+y)

Now with respect to percentages, we have:

$$\frac {10}{100}$$ x + $$\frac {2}{100}$$ y = $$\frac {4}{100}$$ (x+y)

So, canceling all the 100s from the denominators, we get

$$10x + 2y = 4(x+y)$$

Rearranging like terms, we get

(10-4) x = (4-2) y

This implies that:

$$\frac {x}{y}$$ = $$\frac {4-2}{10-4}$$ = $$\frac {2}{6}$$= $$\frac {1}{3}$$

Hope this helps.
Intern
Joined: 07 Jun 2010
Posts: 48
Location: United States
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

24 Jun 2010, 17:13
whiplash2411 wrote:
A similar logic to what I said in the previous question can be used here.

Let us assume he takes x grams of Krisp and y grams of Brano.

So the total weight of the new mixture is (x+y)

Now with respect to percentages, we have:

$$\frac {10}{100}$$ x + $$\frac {2}{100}$$ y = $$\frac {4}{100}$$ (x+y)

So, canceling all the 100s from the denominators, we get

$$10x + 2y = 4(x+y)$$

Rearranging like terms, we get

(10-4) x = (4-2) y

This implies that:

$$\frac {x}{y}$$ = $$\frac {4-2}{10-4}$$ = $$\frac {2}{6}$$= $$\frac {1}{3}$$

Hope this helps.

it should be

(10y + 2x) (x + y)= 4 (xy)
SVP
Status: Three Down.
Joined: 09 Jun 2010
Posts: 1869
Concentration: General Management, Nonprofit
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

24 Jun 2010, 17:25
Can you explain the logic behind that?
Kaplan GMAT Instructor
Joined: 21 Jun 2010
Posts: 71
Location: Toronto
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

26 Jun 2010, 17:47
6
5
Krispo is 10%. Bruno is 2%.

Question. Suppose we wanted the final solution to be 6% (not 4%). Because 6 is the midpoint between 10 and 2, wouldn't it then be clear that we would need the final solution to be half of each, and that ratio would be 1:1? It is helpful to visualize this on the number line:

2...6...10

Here we want the final solution to be 4%. So it looks like this:

2.4.....10

Because the grand average is skewed towards Bruno, in order to make the final solution 4%, clearly we need more Bruno than Krisp. In fact, because 4 is only 2 units away from 2 but 6 units away from 10, we need 6:2 or 3:1 as much Bruno as Krisp or 1:3 Krisp to Bruno.

____________

TAKEAWAY: The amount of skew is inversely proportional to the relative quantities of each item. If we have two groups, A, and B, then we have ("x" and "y" represent distance from the total average):

Average of A-------x-------Total average------y--------Average of B

(# in A)/(# in B) = y/x

This concept recurs fairly frequenly on the GMAT, especially in Data Sufficiency questions. If x and y are integers, then using this approach is quick and effective.
Manager
Joined: 15 Mar 2010
Posts: 81
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

27 Jun 2010, 20:21
4
2
Jinglander wrote:
Can someone walk me through this please

Krisp cereal is 10% sugar by weight. Brano cereal is 2% sugar by weight. If you wanted to make the mixture 4% sugar by weight what should the ratio of krisp to brano.

An Easier approach:

Attachment:

pic.JPG [ 3.37 KiB | Viewed 6203 times ]

Hence the ratio of quantities is 2:6=1/3
_________________

If you like my post, consider giving me a kudos. THANKS!

Intern
Joined: 14 Jul 2009
Posts: 3
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

28 Jun 2010, 05:23
K -->10
B ---> 2
So 10K+2B = (K+B)4 --> 10K+2B = 4K+4B --> 6K = 2B --> K/B = 2/6 = 1/3
Moderator
Joined: 22 Jun 2014
Posts: 1047
Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

09 Apr 2016, 00:42
Jinglander wrote:
Krisp cereal is 10% sugar by weight. Brano cereal is 2% sugar by weight. If you wanted to make the mixture 4% sugar by weight what should the ratio of Krisp to Brano.

Say, w1 is the weight krisp, w2 is the weight of Brano

using weihted average formula w1/w2 = (c2 - avg) / (Avg-c1)

w1/w2 = 4-2 / 10-6 = 2/3

So Krisp and brano should be mixed in the ratio of 1/3.
_________________

---------------------------------------------------------------
Target - 720-740
http://gmatclub.com/forum/information-on-new-gmat-esr-report-beta-221111.html
http://gmatclub.com/forum/list-of-one-year-full-time-mba-programs-222103.html

VP
Joined: 07 Dec 2014
Posts: 1018
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

30 Jul 2016, 20:58
.10k+.02b=.04(k+b)
k/b=1/3
Intern
Joined: 04 Aug 2017
Posts: 10
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su [#permalink]

### Show Tags

13 Oct 2017, 04:55
I approached this algebraically:
X= total weight of Krisp
Y= total weight of Bruno

10x/100 + 2y/100=4(x+y)/100
10x/100 + 2y/100=4x/100 + 4y/100
6x/100=2y/100
6x=2y
x=1/3(y)
x/y=1/3
Re: Krisp cereal is 10% sugar by weight. Brano cereal is 2% su   [#permalink] 13 Oct 2017, 04:55
Display posts from previous: Sort by