It is currently 17 Dec 2017, 02:13

### 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

# If x and y are selected from 2, 3, 4, 5, and 6, what is the

Author Message
Director
Joined: 17 Oct 2005
Posts: 921

Kudos [?]: 282 [0], given: 0

If x and y are selected from 2, 3, 4, 5, and 6, what is the [#permalink]

### Show Tags

21 Mar 2006, 23:24
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If x and y are selected from 2, 3, 4, 5, and 6, what is the probability that x*y is divisible by 4?

Kudos [?]: 282 [0], given: 0

Director
Joined: 05 Feb 2006
Posts: 893

Kudos [?]: 131 [0], given: 0

### Show Tags

22 Mar 2006, 00:35
isn't it 2/5?

5C2 total possible number of picks... = 10
Favourable picks 4

Kudos [?]: 131 [0], given: 0

Intern
Joined: 18 Jan 2006
Posts: 15

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

### Show Tags

22 Mar 2006, 02:22
is it 1/2.

5/5C2

Thanks
_________________

If I cant win, I'll die flying

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

Director
Joined: 05 Feb 2006
Posts: 893

Kudos [?]: 131 [0], given: 0

### Show Tags

22 Mar 2006, 02:31
Gmate wrote:
is it 1/2.

5/5C2

Thanks

Oh yeah, 5 favourable outcomes.... 1/2

Kudos [?]: 131 [0], given: 0

Director
Joined: 17 Oct 2005
Posts: 921

Kudos [?]: 282 [0], given: 0

### Show Tags

22 Mar 2006, 14:57
can you guys elaborate on this one? Is there a quick way or did you guys just calclated all the outcomes? thanks

Kudos [?]: 282 [0], given: 0

Senior Manager
Joined: 11 Nov 2005
Posts: 324

Kudos [?]: 16 [0], given: 0

Location: London

### Show Tags

22 Mar 2006, 15:36
total outcome 10
favorable outcome 5

5/10 = 1/2

Kudos [?]: 16 [0], given: 0

SVP
Joined: 14 Dec 2004
Posts: 1681

Kudos [?]: 173 [0], given: 0

### Show Tags

22 Mar 2006, 22:25
I think we get 6 favorable outcomes.

(2,4) (3,4) (4,4) (5,4) (6,4) (2,6)

Kudos [?]: 173 [0], given: 0

Director
Joined: 05 Feb 2006
Posts: 893

Kudos [?]: 131 [0], given: 0

### Show Tags

23 Mar 2006, 01:18
vivek123 wrote:
I think we get 6 favorable outcomes.

(2,4) (3,4) (4,4) (5,4) (6,4) (2,6)

Nope you can not count 4 and 4, because you have to choose from 2 3 4 5 and 6... there are no two 4s

Kudos [?]: 131 [0], given: 0

Director
Joined: 05 Feb 2006
Posts: 893

Kudos [?]: 131 [0], given: 0

### Show Tags

23 Mar 2006, 01:22
joemama142000 wrote:
can you guys elaborate on this one? Is there a quick way or did you guys just calclated all the outcomes? thanks

We calculated total outcomes by using the combination formula....
n!/(k!(n!-k!))

n! - denotes the total number of choices we have = 5
k! - denotes the number of choices we are arranging = 2

In this example n!=1*2*3*4*5
k!=1*2

And yes, the favourable outcomes are calculated by hand but it does not take long... max 1 minute...

Kudos [?]: 131 [0], given: 0

Manager
Joined: 20 Mar 2005
Posts: 201

Kudos [?]: 16 [0], given: 0

Location: Colombia, South America

### Show Tags

23 Mar 2006, 23:28
vivek123 wrote:
I think we get 6 favorable outcomes.

(2,4) (3,4) (4,4) (5,4) (6,4) (2,6)

in that case (2,2) and (6,6) would work too but it would be over 5^2 = 25

I guess Sima is right

Kudos [?]: 16 [0], given: 0

GMAT Club Legend
Joined: 07 Jul 2004
Posts: 5032

Kudos [?]: 457 [0], given: 0

Location: Singapore

### Show Tags

24 Mar 2006, 00:57
x*y must be a multiple a 4: 4,8,12,16,20,24,28

(x,y) sets

(2,4)
(2,6)
(3,4)
(4,5)
(4,6)

We don't have to consider (4,2) (6,2) (4,3) (5,4) amd (6,4) as we're not interested in placing but groupings.

# of ways ot pick any 2 numbers = 5C2 = 10
P = 5/10 = 1/2

Kudos [?]: 457 [0], given: 0

Director
Joined: 24 Oct 2005
Posts: 658

Kudos [?]: 16 [0], given: 0

Location: London

### Show Tags

24 Mar 2006, 01:54
I got the favourable outcomes as
2 2
2 4
2 6
3 4
4 2
4 3
4 4
4 5
4 6
5 4
6 2
6 4

Total outcomes = 25 (x can be any of the 5 nos and y can be any of the 5 nos.)

Probability = 12/25

Kudos [?]: 16 [0], given: 0

Director
Joined: 02 Mar 2006
Posts: 577

Kudos [?]: 131 [0], given: 0

Location: France

### Show Tags

24 Mar 2006, 07:53
remgeo wrote:
I got the favourable outcomes as
2 2
2 4
2 6
3 4
4 2
4 3
4 4
4 5
4 6
5 4
6 2
6 4

Total outcomes = 25 (x can be any of the 5 nos and y can be any of the 5 nos.)

Probability = 12/25

I had the same result, because no where it is written that once you picked a number, there is one less for the next selection.

Kudos [?]: 131 [0], given: 0

24 Mar 2006, 07:53
Display posts from previous: Sort by

# If x and y are selected from 2, 3, 4, 5, and 6, what is the

Moderator: chetan2u

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.