It is currently 09 Dec 2018, 11:21
My Tests

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.

A certain city has a chance of rain occurring on any given d

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jun 2014
Posts: 4749
GRE 1: Q167 V156
WE: Business Development (Energy and Utilities)
Followers: 93

Kudos [?]: 1650 [0], given: 396

CAT Tests
A certain city has a chance of rain occurring on any given d [#permalink] New post 30 Jul 2018, 11:04
Expert's post
00:00

Question Stats:

64% (00:54) correct 35% (00:44) wrong based on 17 sessions
A certain city has a \(\frac{1}{3}\) chance of rain occurring on any given day. In any given 3-day period, what is the probability that the city experiences rain?

(A) \(\frac{1}{3}\)
(B) \(\frac{8}{27}\)
(C) \(\frac{2}{3}\)
(D) \(\frac{19}{27}\)
(E) \(1\)
[Reveal] Spoiler: OA

_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

Director
Director
User avatar
Joined: 07 Jan 2018
Posts: 550
Followers: 4

Kudos [?]: 476 [0], given: 84

CAT Tests
Re: A certain city has a chance of rain occurring on any given d [#permalink] New post 31 Jul 2018, 07:06
Let us find the possibility of no rain on all of the three days.
It would be \(\frac{2}{3} * \frac{2}{3} * \frac{2}{3} = \frac{8}{27}\)

\(1- \frac{8}{27} = \frac{19}{27}\)

This gives possibility of rain at least on one of those 3 days.
_________________

This is my response to the question and may be incorrect. Feel free to rectify any mistakes

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jun 2014
Posts: 4749
GRE 1: Q167 V156
WE: Business Development (Energy and Utilities)
Followers: 93

Kudos [?]: 1650 [0], given: 396

CAT Tests
Re: A certain city has a chance of rain occurring on any given d [#permalink] New post 21 Aug 2018, 18:34
Expert's post
Explanation

In essence, the question is asking, “What is the probability that one or more days are rainy days?” since any single rainy day would mean the city experiences rain. In this case, employ the 1 – x shortcut, where the probability of rain on one or more days is equal to 1 minus the probability of no rain on any day.

Since the probability of rain is \(\frac{1}{3}\) on any given day, the probability of no rain on any given day is \(1 - \frac{1}{3}=2/3\) .

Therefore, the probability of no rain on three consecutive days is \(\frac{2}{3}\frac{2}{3}\frac{2}{3}=\frac{8}{27}\).

Finally, subtract from 1 to find the probability that it rains on one or more days: P(1 or more days) = 1 – P(no rain) = \(1 - \frac{8}{27}=\frac{19}{27}\).
_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

Re: A certain city has a chance of rain occurring on any given d   [#permalink] 21 Aug 2018, 18:34
Display posts from previous: Sort by

A certain city has a chance of rain occurring on any given d

  Question banks Downloads My Bookmarks Reviews Important topics  


GRE Prep Club Forum Home| About| Terms and Conditions and Privacy Policy| GRE Prep Club Rules| Contact

Powered by phpBB © phpBB Group

Kindly note that the GRE® test is a registered trademark of the Educational Testing Service®, and this site has neither been reviewed nor endorsed by ETS®.