Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 25 May 2017, 02:46

### 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

# Probability Question - Not from a book (No official answer)

Author Message
Intern
Joined: 16 Mar 2010
Posts: 42
Followers: 0

Kudos [?]: 8 [0], given: 39

### Show Tags

07 May 2010, 09:42
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

Hey guys - long time lurker here and this is my first post.

My buddy at work was talking about how he plays a lottery where you pick 4 numbers and there is a drawing everyday, which got me thinking about it in terms of the gmat.

Probability of hitting the 4 numbers in order = 1 / 10^4 = 1/10,000 ?

But you can also "win the lottery" if you pick the 4 numbers correctly, not neccesarily in order.

I'm having a little trouble caluclating that number so if you all can help me understand that would be SUPER!

-Sameer
Intern
Joined: 16 Mar 2010
Posts: 42
Followers: 0

Kudos [?]: 8 [0], given: 39

Re: Probability Question - Not from a book (No official answer) [#permalink]

### Show Tags

10 May 2010, 06:34
Guys come on!!

I thought we were friends!!!!!
Senior Manager
Joined: 25 Jun 2009
Posts: 303
Followers: 2

Kudos [?]: 127 [0], given: 6

Re: Probability Question - Not from a book (No official answer) [#permalink]

### Show Tags

10 May 2010, 07:07
sameermunshi wrote:
Hey guys - long time lurker here and this is my first post.

My buddy at work was talking about how he plays a lottery where you pick 4 numbers and there is a drawing everyday, which got me thinking about it in terms of the gmat.

Probability of hitting the 4 numbers in order = 1 / 10^4 = 1/10,000 ?

But you can also "win the lottery" if you pick the 4 numbers correctly, not neccesarily in order.

I'm having a little trouble caluclating that number so if you all can help me understand that would be SUPER!

-Sameer

Okay, even though I am not an expert but let me give a shot to this one...!

So 4 numbers to choose from ..

so the probability for the 1st number on our lottery ( 4/10 ) because we have 4 numbers to choose from-- assuming we are talking about digits(0-9) here

for 2nd number it should 3/10 and similarly for 3rd number 2/10

So final probablity = $$\frac{(4 *3*2*1)}{10*10*10*10}$$

Cheers,
Intern
Joined: 16 Mar 2010
Posts: 42
Followers: 0

Kudos [?]: 8 [0], given: 39

Re: Probability Question - Not from a book (No official answer) [#permalink]

### Show Tags

10 May 2010, 12:12
Thanks Nitish!

So quick question:

if 4*3*2*1 /10*10*10*10 = Prob of picking 4 numbers (order doesnt matter) out of 10

what would 4*4*4*4 / 10*10*10*10 mean? ?

Anyone else have any input?

Appreciate it!!
nitishmahajan wrote:
sameermunshi wrote:
Hey guys - long time lurker here and this is my first post.

My buddy at work was talking about how he plays a lottery where you pick 4 numbers and there is a drawing everyday, which got me thinking about it in terms of the gmat.

Probability of hitting the 4 numbers in order = 1 / 10^4 = 1/10,000 ?

But you can also "win the lottery" if you pick the 4 numbers correctly, not neccesarily in order.

I'm having a little trouble caluclating that number so if you all can help me understand that would be SUPER!

-Sameer

Okay, even though I am not an expert but let me give a shot to this one...!

So 4 numbers to choose from ..

so the probability for the 1st number on our lottery ( 4/10 ) because we have 4 numbers to choose from-- assuming we are talking about digits(0-9) here

for 2nd number it should 3/10 and similarly for 3rd number 2/10

So final probablity = $$\frac{(4 *3*2*1)}{10*10*10*10}$$

Cheers,
Senior Manager
Joined: 25 Jun 2009
Posts: 303
Followers: 2

Kudos [?]: 127 [0], given: 6

Re: Probability Question - Not from a book (No official answer) [#permalink]

### Show Tags

10 May 2010, 12:27
sameermunshi wrote:
Thanks Nitish!

So quick question:

if 4*3*2*1 /10*10*10*10 = Prob of picking 4 numbers (order doesnt matter) out of 10

what would 4*4*4*4 / 10*10*10*10 mean? ?

Anyone else have any input?

Appreciate it!!
nitishmahajan wrote:
sameermunshi wrote:
Hey guys - long time lurker here and this is my first post.

My buddy at work was talking about how he plays a lottery where you pick 4 numbers and there is a drawing everyday, which got me thinking about it in terms of the gmat.

Probability of hitting the 4 numbers in order = 1 / 10^4 = 1/10,000 ?

But you can also "win the lottery" if you pick the 4 numbers correctly, not neccesarily in order.

I'm having a little trouble caluclating that number so if you all can help me understand that would be SUPER!

-Sameer

Okay, even though I am not an expert but let me give a shot to this one...!

So 4 numbers to choose from ..

so the probability for the 1st number on our lottery ( 4/10 ) because we have 4 numbers to choose from-- assuming we are talking about digits(0-9) here

for 2nd number it should 3/10 and similarly for 3rd number 2/10

So final probablity = $$\frac{(4 *3*2*1)}{10*10*10*10}$$

Cheers,

Well, Say for e.g the case would have been that we need to pick 4 numbers in any order and at any place holder.

For e.g winning lottery number would have been 4678 and so the condition would have been something like 4 numbers
any order like 4468 or may be even 6777 ( I mean to say any number can fit any where even with repetition then

\frac{4*4*4*4}{10*10*10*10}

Would have fit the bill...!

Cheers
Senior Manager
Joined: 21 Jul 2009
Posts: 364
Schools: LBS, INSEAD, IMD, ISB - Anything with just 1 yr program.
Followers: 18

Kudos [?]: 175 [0], given: 22

Re: Probability Question - Not from a book (No official answer) [#permalink]

### Show Tags

10 May 2010, 13:18
Is my understanding wrong??

You have 10 digits from 0 to 9 inclusive. You are selecting one number from the 10 for every place, thus you select 4 times to get a four digit number - (10C1)^4 = 10 * 10 * 10 * 10 = 10000.

All possible 4 digit numbers - 9 * 10 * 10 * 10 = 9000 (have to give up 0 for the first spot).

Probability of choosing a 4 digit number from the entire lot = 10000/9000 = 10/9 > 1.

Is this even possible? what am I doing wrong with the question??
_________________

I am AWESOME and it's gonna be LEGENDARY!!!

Re: Probability Question - Not from a book (No official answer)   [#permalink] 10 May 2010, 13:18
Display posts from previous: Sort by