The safe lock consists of three disks: the first one marked : PS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 23 Jan 2017, 03:15

### 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

# The safe lock consists of three disks: the first one marked

Author Message
SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 245 [0], given: 0

The safe lock consists of three disks: the first one marked [#permalink]

### Show Tags

19 Dec 2003, 01:24
00:00

Difficulty:

(N/A)

Question Stats:

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

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

The safe lock consists of three disks: the first one marked from 0 to 9, the second marked with even digits, and the third marked with 1 and 0. A certain guy has a one attempt to open the safe by rotating disks randomly. Assuming that there is the only correct combination to open the safe, what is the probability that the guy will not open the safe?
Director
Joined: 13 Nov 2003
Posts: 790
Location: BULGARIA
Followers: 1

Kudos [?]: 47 [0], given: 0

### Show Tags

19 Dec 2003, 04:32
anvar, agree with the method offered, but think that on second ring we should coun also 0 which is even, as far as i know, which makes the possible combinations 100( 10x5x2), not 80...
Intern
Joined: 27 Nov 2003
Posts: 33
Location: Moscow
Followers: 0

Kudos [?]: 1 [0], given: 0

### Show Tags

19 Dec 2003, 04:34
BG wrote:
anvar, agree with the method offered, but think that on second ring we should coun also 0 which is even, as far as i know, which makes the possible combinations 100( 10x5x2), not 80...

Thanks BG, good to know that "zero" is even
_________________

me

Intern
Joined: 22 Nov 2003
Posts: 41
Location: Serbia
Followers: 0

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

### Show Tags

19 Dec 2003, 09:03

(analogy with 750+ on GMAT)
SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 245 [0], given: 0

### Show Tags

19 Dec 2003, 09:06
99% is OK
to be perfect, let's transform the number into 0.99.
according to math definition of probability, 0<=P<=1
SVP
Joined: 30 Oct 2003
Posts: 1793
Location: NewJersey USA
Followers: 5

Kudos [?]: 98 [0], given: 0

### Show Tags

05 Jan 2004, 14:50
Probability that he will open the lock
= 1/10 * 1/5 * 1/2

probability that he wont open the lock = 1 - 1/100 = 0.99
05 Jan 2004, 14:50
Display posts from previous: Sort by

# The safe lock consists of three disks: the first one marked

 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®.