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Stuart@KaplanGMAT: GMAT Instructor; Posts: 3225; Joined: Tue Jan 08, 2008 2:40 pm; Location: Toronto; Thanked: 1710 times; Followed by:614 members; GMAT Score:800

by Stuart@KaplanGMAT » Tue Apr 12, 2011 10:11 am

prashkrish wrote:Why is the following not a possible outcome?

B, G, P, R refer to number of balls.

(11 * R) * (1 * B) * (5 * G) * (x * P) = 88,000

If the following 2 outcomes could occur..
(11 * R) * (1 * B) * (5 * G) * (x * P) = (11 * 1) * (1 * 10) * (5 * 20) * (8 * 1)

OR

(11 * R) * (B * 1) * (5 * G) * (x * P) = (11 * 1) * (1 * 8) * (5 * 20) * (10 * 1)

Purple could be 8 or 10..

Please help me understand...

As noted in my post above, you multiply the value of each chip by the values of all of the other chips.

So, if you have 1 blue chip, the total value of the blues is:

1^1 = 1.

Similarly, if you have 10 blue chips, the total value of the blues is:

1^10 = 1

not

1*10 = 10

which is what you did in your calculation.

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

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maihuna: Legendary Member; Posts: 1578; Joined: Sun Dec 28, 2008 1:49 am; Thanked: 82 times; Followed by:9 members; GMAT Score:720

by maihuna » Tue Apr 12, 2011 10:11 am

Ok got it, thanks Stuart as always. I think, though, the wordings are too weird.

Stuart Kovinsky wrote:
maihuna wrote:Stuart : I am more confused about the following constraints: have you thought of that. Is the worth of purple chips more than green and less than the red ones:

How many Purple : 2 with 8 each = 8*2 = 16
Green : 3 with 5 each = 3*5 = 15
Red : 1 with 11 = 1*11 = 11

so 11<15<16 or R<G<P

What am I missing here?

mmukher wrote: The purple chips are worth more than the green chips, but less than the red chips. A certain number of chips are then selected from the bag.
You're misinterpreting the statement to read "the sum of the purple chips is greater than that of the green chips, but less than that of the red chips"; it's not the sums that are being compared, but the values of the individual chips.

As we can see from the question:

In a certain game, a large bag is filled with blue, green, purple and red chips worth 1, 5, x and 11 points each, respectively.
"respectively" means that you take them in the order given; in other words, blue chips are worth 1 each, green chips are worth 5 each, purple chips are worth x each and red chips are worth 11 each.

Charged up again to beat the beast

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eubschoolasp: Junior | Next Rank: 30 Posts; Posts: 15; Joined: Sat Jun 04, 2011 7:10 am; Location: New Delhi; GMAT Score:710

by eubschoolasp » Sat Jun 11, 2011 9:37 am

Hi Stuart
I'm sorry but when it says "The purple chips are worth more than the green chips, but less than the red chips", for me it implies the 'worth' of the purple chips is being considered, and that would be the point for purple chips multiplied by the number of purple chips. I would agree with people that the language used indeed is ambiguous. To avoid any possible ambiguity, it should have clearly mentioned that the point value is lesser/ greater. Isn't it?

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Ahmed MS: Senior | Next Rank: 100 Posts; Posts: 74; Joined: Wed Apr 06, 2011 8:35 pm; Followed by:1 members

by Ahmed MS » Wed Jun 15, 2011 5:11 am

First break down the value 88,000.

For example 88,000 / 5 =17,600

17,600 / 5 = 3,520

3,520 / 5 = 704

704/ 8 = 88

88 / 8 =11

Blue chips worth 1, so we can ignore it. Let take all the multiple values of 88,000.

So, it would be 5 * 5* 5* 8* 8* 11 = 88,000

As Blue = 1, Green =5, Red = 11 are given so obviously Purple = 8 (indeed)

Therefore we need 2 purple chips. Answer is "B"

I think we should come with easier and faster way to solve the problem as we will have very limited time in the real GMAT Exam.

Cheers!

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Michelleleigha: Newbie | Next Rank: 10 Posts; Posts: 2; Joined: Thu Jun 30, 2011 12:57 pm

by Michelleleigha » Wed Jul 06, 2011 5:45 am

there are 2 8's so the answer is B

88* 1000= 88,000
11*8= 88
5*5*5*8= 1000

I like to use the factor trees for quick results.

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akhilsuhag: Master | Next Rank: 500 Posts; Posts: 351; Joined: Mon Jul 04, 2011 10:25 pm; Thanked: 57 times; Followed by:4 members

by akhilsuhag » Sun Jul 10, 2011 12:37 am

this is how I did it:

88,000 = 11*5*5*5*64

Now 64 will be a multiple of x ans x is between 5 & 11 (6,7,8,9,10).

This leaves x= 8.

now, 8*8 = 64..
Therefore 2 8's.

So, x= 8 and we have 2 x's.

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saurabh2525_gupta: Senior | Next Rank: 100 Posts; Posts: 72; Joined: Wed Oct 27, 2010 2:06 am; Thanked: 2 times; Followed by:1 members

by saurabh2525_gupta » Tue Jul 12, 2011 8:44 pm

The worth of purple chips has to be 8 because of above explained reasons. But the answer can A as well as B. This is how:-

We need a total product of 88000.
RED PURPLE GREEN BLUE
1*11 * 1*8 * 5*200 1*1 answer in this case is A
1*11 * 2*8 * 5*100 1*1 answer in this case is B

There is no restriction on the number of chips that have to be picked.

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madhavsingh: Newbie | Next Rank: 10 Posts; Posts: 1; Joined: Sun Jul 10, 2011 7:31 am

by madhavsingh » Fri Jul 15, 2011 10:45 pm

value of purple chip is 8.
number of purple chips can be either one of these nos: 1, 2, 4,5,8,10 ( and many others, including 1000).
The maximum no of purple chips is 1000.

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saketk: Legendary Member; Posts: 608; Joined: Sun Jun 19, 2011 11:16 am; Thanked: 37 times; Followed by:8 members

by saketk » Wed Aug 17, 2011 10:37 am

Blue- 1 -- total 1 or many doesn't matter as it's value is 1.
Green - 5 -- total 3
Purple - X --- total 2
Red - 11-- total 1
Note: I did this orally, so the total written against each was calculated after the prime factorization of 88000.

Given...

11>X>5

88000 =

2*5*2*5*2*5*11*2*2*2
8*8*5*5*5*11*1

To fit the condition, C can only be 8. Therefore, total 2.. Answer choice B

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Deependra1: Senior | Next Rank: 100 Posts; Posts: 53; Joined: Sun Apr 10, 2011 12:15 pm; Thanked: 1 times

by Deependra1 » Fri Aug 26, 2011 10:15 am

Answer should be C

hopefully

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jsnipes: Junior | Next Rank: 30 Posts; Posts: 27; Joined: Tue Mar 08, 2011 7:41 am; Thanked: 1 times

by jsnipes » Mon Sep 12, 2011 7:07 am

i need to get better at 'interpreting' these questions.

i just looked at and realized that 1x5x11=55. so in order to get to an even number such as 88k it would have to be multiplied by an even number. both 2 and 4 work in the answer column but i didn't know how to get to that last step and just guessed (the right guess, but irrelevant). thanks for the fine explanation stuart.

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shourav rahman: Newbie | Next Rank: 10 Posts; Posts: 3; Joined: Fri May 20, 2011 8:01 am

by shourav rahman » Mon Sep 12, 2011 8:11 am

each and every gmat verbal and quant questions of beat the gmat really imporves my basic. thnx beat the gmat and all of the participants.

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smitalli: Newbie | Next Rank: 10 Posts; Posts: 1; Joined: Wed Sep 21, 2011 9:21 pm

by smitalli » Tue Sep 27, 2011 7:56 am

I get confused in what the question is asking. I understand how you got the answer but from the beginning I didn't know what the question was looking for. What does it mean by "the product of the point values", is it just the obvious. All the values multiplied by themselves equals 88,000?

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way2ashish: Senior | Next Rank: 100 Posts; Posts: 32; Joined: Mon Sep 26, 2011 6:34 pm

by way2ashish » Fri Sep 30, 2011 5:18 pm

Hi,
I dint get the last step

To get 2^6, we need two 8s: choose (b). ???
could u please elaborate on this

Stuart Kovinsky wrote:
mmukher wrote:In a certain game, a large bag is filled with blue, green, purple and red chips worth 1, 5, x and 11 points each, respectively. The purple chips are worth more than the green chips, but less than the red chips. A certain number of chips are then selected from the bag. If the product of the point values of the selected chips is 88,000, how many purple chips were selected?

Options :
1
2
3
4
5

OA later.
We know that the purple chips are worth 6, 7, 8, 9 or 10 points each.

The blue chips are worth 1 point each, so we can ignore those.

Let's break 88000 down to primes:

88 * 1000

11 * 8 * 10 * 10 * 10

11 * 2 * 2 * 2 * 2 * 5 * 2 * 5 * 2 * 5

so:

2^6 * 5^3 * 11

Well, we're not getting any 2s out of the 1, 5 or 11, so all the 2s have to come from x.

Therefore, x has to be 6, 8 or 10.

x can't be 6, because we don't want any 3s.

If x were 10, it would give us 2s and 5s. So to get 6 2s we'd also have to take 6 5s, which is way more than we want.

Therefore, x MUST be 8.

To get 2^6, we need two 8s: choose (b).

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Rastis: Master | Next Rank: 500 Posts; Posts: 183; Joined: Wed Sep 21, 2011 7:06 am; Location: Washington, DC; Thanked: 6 times; Followed by:2 members; GMAT Score:500