Find all School-related info fast with the new School-Specific MBA Forum

It is currently 01 Aug 2015, 14:59
GMAT Club Tests

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

20 cards are numbered 1-20 and drawn randomly from a hat and

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 10 Feb 2007
Posts: 3
Followers: 0

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

20 cards are numbered 1-20 and drawn randomly from a hat and [#permalink] New post 10 Feb 2007, 14:32
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

20 cards are numbered 1-20 and drawn randomly from a hat and not replaced. How many have to be drawn in order to ensure that the sum of all the cards drawn is even?

3
10
11
12
19
Intern
Intern
avatar
Joined: 02 Jan 2007
Posts: 41
Followers: 0

Kudos [?]: 2 [0], given: 0

 [#permalink] New post 10 Feb 2007, 15:31
I guess this is as much a probability as it is a number property problem. Anyway, I say 11.
_________________

Beginning with the end in mind. Aiming to join the 700+ club.

Senior Manager
Senior Manager
User avatar
Joined: 04 Jan 2006
Posts: 279
Followers: 1

Kudos [?]: 24 [0], given: 0

 [#permalink] New post 10 Feb 2007, 18:52
trivikram wrote:
11

1 Even + 10 Odd


This is still odd. I think you have to draw another card (odd card) to get

1 Even + 10 Odd + another one odd = Even number

12 is the answer for me.
VP
VP
avatar
Joined: 28 Mar 2006
Posts: 1383
Followers: 2

Kudos [?]: 20 [0], given: 0

 [#permalink] New post 10 Feb 2007, 19:15
devilmirror wrote:
trivikram wrote:
11

1 Even + 10 Odd


This is still odd. I think you have to draw another card (odd card) to get

1 Even + 10 Odd + another one odd = Even number

12 is the answer for me.


1 Even + 2*(5 Odd) = Even Number

Also we used all the 10 odd numbers so you dont have another odd number to add :)
Senior Manager
Senior Manager
User avatar
Joined: 04 Jan 2006
Posts: 279
Followers: 1

Kudos [?]: 24 [0], given: 0

 [#permalink] New post 10 Feb 2007, 20:08
trivikram wrote:
devilmirror wrote:
trivikram wrote:
11

1 Even + 10 Odd


This is still odd. I think you have to draw another card (odd card) to get

1 Even + 10 Odd + another one odd = Even number

12 is the answer for me.


1 Even + 2*(5 Odd) = Even Number

Also we used all the 10 odd numbers so you dont have another odd number to add :)


Silly me. :oops:
Senior Manager
Senior Manager
avatar
Joined: 19 Jul 2006
Posts: 361
Followers: 1

Kudos [?]: 3 [0], given: 0

 [#permalink] New post 10 Feb 2007, 21:17
devilmirror wrote:
trivikram wrote:
devilmirror wrote:
trivikram wrote:
11

1 Even + 10 Odd


This is still odd. I think you have to draw another card (odd card) to get

1 Even + 10 Odd + another one odd = Even number

12 is the answer for me.


1 Even + 2*(5 Odd) = Even Number

Also we used all the 10 odd numbers so you dont have another odd number to add :)


Silly me. :oops:


Now i like to change my Answer to 12 .. I think devilmirror was correct


What happens if say in Eleven draws get 10 even numbers and 1 odd ..
then 10 even numbers + 1 odd = odd
VP
VP
avatar
Joined: 28 Mar 2006
Posts: 1383
Followers: 2

Kudos [?]: 20 [0], given: 0

 [#permalink] New post 10 Feb 2007, 21:18
AK wrote:
devilmirror wrote:
trivikram wrote:
devilmirror wrote:
trivikram wrote:
11

1 Even + 10 Odd


This is still odd. I think you have to draw another card (odd card) to get

1 Even + 10 Odd + another one odd = Even number

12 is the answer for me.


1 Even + 2*(5 Odd) = Even Number

Also we used all the 10 odd numbers so you dont have another odd number to add :)


Silly me. :oops:


Now i like to change my Answer to 12 .. I think devilmirror was correct


What happens if say in Eleven draws get 10 even numbers and 1 odd ..
then 10 even numbers + 1 odd = odd


Wonderful...Atleast 1 guy was thinking out of box :-D ...it should be 12
Intern
Intern
avatar
Joined: 20 Jan 2007
Posts: 18
Followers: 0

Kudos [?]: 9 [0], given: 0

 [#permalink] New post 11 Feb 2007, 05:26
If you take 12 cards and say you take:

2 4 6 8 10 12 14 = 56
1 3 5 7 9 = 25

This adds an odd number

I would say it is E: 19
Senior Manager
Senior Manager
avatar
Joined: 23 Jun 2006
Posts: 387
Followers: 1

Kudos [?]: 312 [0], given: 0

 [#permalink] New post 11 Feb 2007, 06:25
even 19 is not enough....
you can still get 9 odd and 10 even...

however, i think the question is not wroded carefully...

when you say you draw n cards... do you mean that the n cards drawn have an even sum, or do you mean that UNTIL the Nth card drawn you get at an even sum on the way (i.e. maybe the (n-1) first cards or (n-2) first cards have even sum)...

if you simply draw n cards and expect to get an even sum - then you must draw ALL 20 cards.below that you can always come with a combination of odd number of odd cards and whatever number of even cards to complete it.
Intern
Intern
avatar
Joined: 20 Jan 2007
Posts: 18
Followers: 0

Kudos [?]: 9 [0], given: 0

 [#permalink] New post 11 Feb 2007, 07:01
hobbit wrote:
even 19 is not enough....
you can still get 9 odd and 10 even...

however, i think the question is not wroded carefully...

when you say you draw n cards... do you mean that the n cards drawn have an even sum, or do you mean that UNTIL the Nth card drawn you get at an even sum on the way (i.e. maybe the (n-1) first cards or (n-2) first cards have even sum)...

if you simply draw n cards and expect to get an even sum - then you must draw ALL 20 cards.below that you can always come with a combination of odd number of odd cards and whatever number of even cards to complete it.


You are correct, hobbit. I thought of it while having lunch. You must have all the cards (that is 20) drawn to get an even sum.
  [#permalink] 11 Feb 2007, 07:01
Display posts from previous: Sort by

20 cards are numbered 1-20 and drawn randomly from a hat and

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.