GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 09 Dec 2019, 19:12

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.

Close

Request Expert Reply

Confirm Cancel

In a box there are 90 slips, numbered from 1 to 90. John picks up four

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
S
Joined: 18 Jul 2019
Posts: 54
Premium Member Reviews Badge CAT Tests
In a box there are 90 slips, numbered from 1 to 90. John picks up four  [#permalink]

Show Tags

New post 25 Nov 2019, 07:08
5
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

33% (02:05) correct 67% (01:21) wrong based on 15 sessions

HideShow timer Statistics

In a box there are 90 slips, numbered from 1 to 90. John picks up four slips at random, one after the other, without replacement. What is the probability that the numbers on the slips, in the order he picks them up, are in ascending order?

(A)\(\frac{1}{6}\)

(B)\(\frac{1}{12}\)

(C)\(\frac{1}{24}\)

(D)\(\frac{1}{45}\)

(E) \(\frac{1}{49}\)
Intern
Intern
avatar
B
Joined: 02 Oct 2016
Posts: 9
CAT Tests
Re: In a box there are 90 slips, numbered from 1 to 90. John picks up four  [#permalink]

Show Tags

New post 25 Nov 2019, 19:57
CaptainLevi wrote:
In a box there are 90 slips, numbered from 1 to 90. John picks up four slips at random, one after the other, without replacement. What is the probability that the numbers on the slips, in the order he picks them up, are in ascending order?

(A)\(\frac{1}{6}\)

(B)\(\frac{1}{12}\)

(C)\(\frac{1}{24}\)

(D)\(\frac{1}{45}\)

(E) \(\frac{1}{49}\)


All combination of selecting number is P(n,k) *permutation.There are exactly C(n,k) combination for the ascending one.So, it is C(n,k)/P(n,k) = 1/k!. For the current question it is 1/4! = 1/24
Intern
Intern
avatar
Joined: 10 Aug 2018
Posts: 1
Re: In a box there are 90 slips, numbered from 1 to 90. John picks up four  [#permalink]

Show Tags

New post 26 Nov 2019, 12:52
Can someone explain this with more details, please?
GMAT Club Bot
Re: In a box there are 90 slips, numbered from 1 to 90. John picks up four   [#permalink] 26 Nov 2019, 12:52
Display posts from previous: Sort by

In a box there are 90 slips, numbered from 1 to 90. John picks up four

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne