It is currently 22 Feb 2018, 20:50

### 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

# Prob & Comb mix- solve using Bernoulli Theorem

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Intern
Joined: 17 Feb 2008
Posts: 28
Prob & Comb mix- solve using Bernoulli Theorem [#permalink]

### Show Tags

10 Mar 2009, 23:16
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

25. John wrote a phone number on a note that was later lost. John can remember that the number had 7 digits, the digit 1 appeared in the last three places and 0 did not appear at all. What is the probability that the phone number contains at least two prime digits?

a) 15/16
b) 11/16
c) 11/12
d) ½
e) 5/8

----------------------------------------
The answer is 11/16, but I cant seem to get it using bernouli theorem:

P^s(1-P)^n-s nCr

Words: Prob of success x 1 - prob of failure x combinations

Can someone please solve using this method or show me a simpler way and please dumb it down... Cheers
Intern
Joined: 03 Jan 2009
Posts: 11
Re: Prob & Comb mix- solve using Bernoulli Theorem [#permalink]

### Show Tags

11 Mar 2009, 06:50
25. John wrote a phone number on a note that was later lost. John can remember that the number had 7 digits, the digit 1 appeared ONLY in the last three places and 0 did not appear at all. What is the probability that the phone number contains at least two prime digits?

Try now... you will get the answer you are looking for
Re: Prob & Comb mix- solve using Bernoulli Theorem   [#permalink] 11 Mar 2009, 06:50
Display posts from previous: Sort by

# Prob & Comb mix- solve using Bernoulli Theorem

 post reply Question banks Downloads My Bookmarks Reviews Important topics

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®.