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

 It is currently 23 Sep 2018, 01:34

### 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 leap year, find the probability that there are exactly

Author Message
TAGS:

### Hide Tags

Intern
Joined: 12 Dec 2017
Posts: 3
in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

Updated on: 08 Mar 2018, 12:52
1
3
00:00

Difficulty:

45% (medium)

Question Stats:

66% (01:33) correct 34% (00:40) wrong based on 47 sessions

### HideShow timer Statistics

In a leap year, find the probability that there are exactly 5 Mondays in the month of September?

a. 1/7
b. 2/7
c. 3/7
d. 4/7
e. 5/7

Originally posted by kanakdaga on 08 Mar 2018, 11:38.
Last edited by pushpitkc on 08 Mar 2018, 12:52, edited 1 time in total.
BSchool Forum Moderator
Joined: 26 Feb 2016
Posts: 3136
Location: India
GPA: 3.12
Re: in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

08 Mar 2018, 12:57
1
kanakdaga wrote:
In a leap year, find the probability that there are exactly 5 Mondays in the month of September?

a. 1/7
b. 2/7
c. 3/7
d. 4/7
e. 5/7

Since there are 30 days in the month of September, there are exactly 4 weeks and 2 extra days.

There are 2 possibilities that the month will have 5 Mondays.
1. When the first day is a Monday(1,8,15,22,29)
2. When the first day in a Sunday(2,9,16,23,30)

Therefore, the probability that there are exactly 5 Mondays is $$\frac{2}{7}$$(Option B)
_________________

You've got what it takes, but it will take everything you've got

Senior Manager
Joined: 31 May 2017
Posts: 325
Re: in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

08 Mar 2018, 23:17
September month has 30 days. Out of which the probability of having 5 monday's will occur only 2 conditions. Either the week starts with Sunday or week starts with Monday.

There are 2 possibility out of 7.

Ans: Option B - 2/7
_________________

Please give kudos if it helps

Resources
| | | | |

Moderator
Joined: 29 Jan 2015
Posts: 917
Location: India
WE: General Management (Non-Profit and Government)
Re: in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

13 Mar 2018, 11:23
kanakdaga wrote:
In a leap year, find the probability that there are exactly 5 Mondays in the month of September?

a. 1/7
b. 2/7
c. 3/7
d. 4/7
e. 5/7

Good question. Took me some time to figure it out.

Since September has 30 days then it will have 5 Mondays only if the 1st day of the month is a Monday or a Sunday.

Hence the probability is 2/7. So B.
_________________

If you liked my post, kindly give me a Kudos. Thanks.

Director
Joined: 27 May 2012
Posts: 575
Re: in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

15 Mar 2018, 05:47
rohan2345 wrote:
kanakdaga wrote:
In a leap year, find the probability that there are exactly 5 Mondays in the month of September?

a. 1/7
b. 2/7
c. 3/7
d. 4/7
e. 5/7

Good question. Took me some time to figure it out.

Since September has 30 days then it will have 5 Mondays only if the 1st day of the month is a Monday or a Sunday.

Hence the probability is 2/7. So B.

Sorry, but how is the total possible outcome 7, is it possible for a month to have 7 Mondays .
So 2 Mondays out of 7 hence 2/7 ?
_________________

- Stne

Board of Directors
Status: Stepping into my 10 years long dream
Joined: 18 Jul 2015
Posts: 3672
Re: in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

15 Mar 2018, 05:58
1
stne wrote:

Sorry, but how is the total possible outcome 7, is it possible for a month to have 7 Mondays .
So 2 Mondays out of 7 hence 2/7 ?

Hey stne ,

No, you didn't understand the solution properly.

What we are saying is inorder to have 5 Mondays we need to have 1st day of the month either a Monday or a Sunday.

Now, Probability = Number of favourable outcomes/Total number of outcomes.

Number of favourable outcomes (1st day as Monday or Sunday) = 2
Total number of outcomes(1st day could be any of the 7 days) = 7

Hence, Probability = 2/7.

Does that make sense?
_________________

My GMAT Story: From V21 to V40
My MBA Journey: My 10 years long MBA Dream
My Secret Hacks: Best way to use GMATClub | Importance of an Error Log!
Verbal Resources: All SC Resources at one place | All CR Resources at one place

GMAT Club Inbuilt Error Log Functionality - View More.
New Visa Forum - Ask all your Visa Related Questions - here.

Find a bug in the new email templates and get rewarded with 2 weeks of GMATClub Tests for free

Intern
Joined: 13 Mar 2018
Posts: 7
Re: in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

15 Mar 2018, 06:01
It ddefinitely has to be option B. That is my answer.
Director
Joined: 27 May 2012
Posts: 575
Re: in a leap year, find the probability that there are exactly  [#permalink]

### Show Tags

15 Mar 2018, 07:25
abhimahna wrote:
stne wrote:

Sorry, but how is the total possible outcome 7, is it possible for a month to have 7 Mondays .
So 2 Mondays out of 7 hence 2/7 ?

Hey stne ,

No, you didn't understand the solution properly.

What we are saying is inorder to have 5 Mondays we need to have 1st day of the month either a Monday or a Sunday.

Now, Probability = Number of favourable outcomes/Total number of outcomes.

Number of favourable outcomes (1st day as Monday or Sunday) = 2
Total number of outcomes(1st day could be any of the 7 days) = 7

Hence, Probability = 2/7.

Does that make sense?

Yes now its clear, thanks a ton.
_________________

- Stne

Re: in a leap year, find the probability that there are exactly &nbs [#permalink] 15 Mar 2018, 07:25
Display posts from previous: Sort by

# in a leap year, find the probability that there are exactly

## Events & Promotions

 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®.