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

 It is currently 09 Dec 2019, 19:12

### 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

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

Author Message
TAGS:

### Hide Tags

Manager
Joined: 18 Jul 2019
Posts: 54
In a box there are 90 slips, numbered from 1 to 90. John picks up four  [#permalink]

### Show Tags

25 Nov 2019, 07:08
5
00:00

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
Joined: 02 Oct 2016
Posts: 9
Re: In a box there are 90 slips, numbered from 1 to 90. John picks up four  [#permalink]

### Show Tags

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
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

26 Nov 2019, 12:52
Can someone explain this with more details, please?
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