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

 It is currently 28 Apr 2015, 05:07

### 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

# A is given a phone list containing 200 different phone

Author Message
TAGS:
CEO
Joined: 15 Aug 2003
Posts: 3469
Followers: 61

Kudos [?]: 701 [0], given: 781

A is given a phone list containing 200 different phone  [#permalink]  06 Dec 2003, 16:26
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
24.A is given a phone list containing 200 different phone
numbers. B is given the same phone list A and B are ask to call one phone
number at the same time.

a. What is the probability that A and B call the same number?

b. What is the probability that A and B call a specific number?

Is a different from b.
Director
Joined: 28 Oct 2003
Posts: 503
Location: 55405
Followers: 1

Kudos [?]: 10 [0], given: 0

Quote:
a. What is the probability that A and B call the same number?

1/200.

Quote:
b. What is the probability that A and B call a specific number?

the probability that A calls a specific number:1/200
the probability that B calls the same specific number: 1/200

1/40000 is the probability of both A and B calling the same, prespecified.

This might be confusing, but try to look at it this way, and assume the numbers are simply 1,2,3,4...200

A could call any of these numbers, so there's a 1/200 chance of A calling a specific number, say, #153
B could call any of these numbers, so there's a 1/200 chance of B calling a specific number, say, #153
1/40000 is the chance of A and B both calling #153.

but, the odds of A and B calling the same number (any number) is still 1/200.

I can try again if this makes no sense.
GMAT Instructor
Joined: 07 Jul 2003
Posts: 770
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 13

Kudos [?]: 52 [0], given: 0

stoolfi wrote:
Quote:
a. What is the probability that A and B call the same number?

1/200.

Quote:
b. What is the probability that A and B call a specific number?

the probability that A calls a specific number:1/200
the probability that B calls the same specific number: 1/200

1/40000 is the probability of both A and B calling the same, prespecified.

This might be confusing, but try to look at it this way, and assume the numbers are simply 1,2,3,4...200

A could call any of these numbers, so there's a 1/200 chance of A calling a specific number, say, #153
B could call any of these numbers, so there's a 1/200 chance of B calling a specific number, say, #153
1/40000 is the chance of A and B both calling #153.

but, the odds of A and B calling the same number (any number) is still 1/200.

I can try again if this makes no sense.

The easiest way to explain 1 is to say:

No matter what number A calls, there is a 1/200 chance that B will match it. Hence, the prob is 1/200.
_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

CEO
Joined: 15 Aug 2003
Posts: 3469
Followers: 61

Kudos [?]: 701 [0], given: 781

stoolfi wrote:
Quote:
a. What is the probability that A and B call the same number?

1/200.

Quote:
b. What is the probability that A and B call a specific number?

the probability that A calls a specific number:1/200
the probability that B calls the same specific number: 1/200

1/40000 is the probability of both A and B calling the same, prespecified.

This might be confusing, but try to look at it this way, and assume the numbers are simply 1,2,3,4...200

A could call any of these numbers, so there's a 1/200 chance of A calling a specific number, say, #153
B could call any of these numbers, so there's a 1/200 chance of B calling a specific number, say, #153
1/40000 is the chance of A and B both calling #153.

but, the odds of A and B calling the same number (any number) is still 1/200.

I can try again if this makes no sense.

perfect.

for question 1
A could pick any #....we tell A to pick a number. Then ask B to go pick the same number. that would be 1/200 prob.

for question 2
We give both of them a number ..say 153..and go ask them to pick that number... then prob that A picks it is 1/200 and B picks it is 1/200

thanks stoolfi
praetorian
Similar topics Replies Last post
Similar
Topics:
11 Free GMAT Toolkit iPhone App with 25 Kudos or 200 Posts 16 19 Oct 2011, 13:37
Phone Interviews 0 16 Sep 2010, 20:13
Phone Interview 2 30 May 2007, 10:01
Phone interview 2 06 Jan 2007, 20:04
Phone interivew... 4 19 Dec 2006, 12:21
Display posts from previous: Sort by