GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video
close
It is currently 08 May 2021, 01:57
Register
GMAT Club Tests
Decision Tracker
My Rewards
New posts
New comers' posts

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.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel
If a number is selected at random from a set of 6 distinct integers
6 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
Tags:
Find Similar Topics 

Show Tags
Hide Tags

User avatar
V
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 74518
CAT Tests Top Member of the Month
If a number is selected at random from a set of 6 distinct integers [#permalink] New post  26 Nov 2019, 00:33
3
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

35% (medium)

Question Stats:

66% (01:16) correct 34% (01:15) wrong based on 196 sessions

Hide Show timer Statistics

If a number is selected at random from a set of 6 distinct integers, what is the probability that the number is odd or prime?

(1) The probability of the number being odd is \(\frac{1}{6}\).
(2) The probability of the number being prime is \(\frac{1}{3}\).


Are You Up For the Challenge: 700 Level Questions
ShowHide Answer
Official Answer
Official Answer and Stats are available only to registered users. Register/Login.

_________________
New to the GMAT CLUB Forum?
Posting Rules: QUANTITATIVE | VERBAL. Guides and Resources: QUANTITATIVE | VERBAL | Ultimate GMAT Quantitative Megathread | All You Need for Quant

Questions' Banks and Collection:
PS: Standard deviation | Tough Problem Solving Questions With Solutions | Probability and Combinations Questions With Solutions | Tough and tricky exponents and roots questions | 12 Easy Pieces (or not?) | Bakers' Dozen | Algebra set | Mixed Questions | Fresh Meat
DS: DS Standard deviation | Inequalities | 700+ GMAT Data Sufficiency Questions With Explanations | Tough and tricky exponents and roots questions | The Discreet Charm of the DS | Devil's Dozen!!! | Number Properties set | New DS set
MIXED: GMAT Club's Complete Questions' Bank | SEVEN SAMURAI OF 2012 | Tricky questions from previous years. | Special Questions' Directory | Best Of The Best Of 2017 | The Best Of Quant of 2016 | 20 hardest and 20 best questions of 2015 | 15 best topics of 2015 | Seven Samurai of 2012 | GMAT Probability Questions

What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
User avatar
V
nick1816
DS Forum Moderator
Joined: 19 Oct 2018
Posts: 2266
Location: India
Re: If a number is selected at random from a set of 6 distinct integers [#permalink] New post  26 Nov 2019, 02:24
1
Kudos
Statement 1-
There is 5 even numbers and 1 odd number

There can be 0,1 or 2 prime numbers

Insufficient

Statement 2-
There are 2 prime numbers; we will have at least 1 odd number

Insufficient

Combining both statements
We have 2 prime numbers (one odd and one even) and we have only 1 odd number, which is prime too.

Sufficient




Bunuel wrote:
If a number is selected at random from a set of 6 distinct integers, what is the probability that the number is odd or prime?

(1) The probability of the number being odd is \(\frac{1}{6}\).
(2) The probability of the number being prime is \(\frac{1}{3}\).


Are You Up For the Challenge: 700 Level Questions
avatar
D
exc4libur
SVP
SVP
Joined: 24 Nov 2016
Posts: 1890
Location: United States
Re: If a number is selected at random from a set of 6 distinct integers [#permalink] New post  26 Nov 2019, 03:41
2
Kudos
Bunuel wrote:
If a number is selected at random from a set of 6 distinct integers, what is the probability that the number is odd or prime?

(1) The probability of the number being odd is \(\frac{1}{6}\).
(2) The probability of the number being prime is \(\frac{1}{3}\).


(1) The probability of the number being odd is \(\frac{1}{6}\). insufic

odd/6=1/6, one odd and five even: {1,2,4,6,8,10}; (odd,prime)/6 = 1/6
odd/6=1/6, one odd and five even: {2,3,4,6,8,10}; (odd,prime)/6 = 2/6

(2) The probability of the number being prime is \(\frac{1}{3}\). insufic

prime/6=1/3: two primes {1,2,3,6,8,10}; (odd,prime)/6 = {1,2,3}/6 = 3/6
prime/6=1/3: two primes: {2,3,4,6,8,10}; (odd,prime)/6 = {2,3}/6

(1&2) sufic

Only even prime number is 2, the others are odd;
If there is only one odd, and two primes, then there is one odd prime and one even prime;
{odd,prime}/6=2/6=1/3

Ans (C)
avatar
B
luukav
Intern
Intern
Joined: 08 Jan 2019
Posts: 4
Re: If a number is selected at random from a set of 6 distinct integers [#permalink] New post  26 Nov 2019, 05:15
As we don't know which distinct numbers are in the set, to know the possibility of the number being odd or prime we need to know more about which numbers are in the set i.e. the range.

Statement 1:
The probability of the number being odd is 1/6.
This doesn't tell us anything about the probability of the number being prime. There are many odd numbers that are prime.

Statement 2:
The probability of the number being prime is 1/3.
This tell us that most of the numbers are odd, except the number two which is prime and even. So there are still multiple outcomes.

Both statements together gives us the information we need to solve the probability for odd or prime.

C IMO
User avatar
P
MHIKER
VP
VP
Joined: 14 Jul 2010
Status:No dream is too large, no dreamer is too small
Posts: 1452
Re: If a number is selected at random from a set of 6 distinct integers [#permalink] New post  08 Jan 2021, 08:30
Top Contributor
Bunuel wrote:
If a number is selected at random from a set of 6 distinct integers, what is the probability that the number is odd or prime?

(1) The probability of the number being odd is \(\frac{1}{6}\).
(2) The probability of the number being prime is \(\frac{1}{3}\).


(1) The set may prime, composite, odd, even. We are given the probability of an odd number only. Insufficient.

(2) The set may prime, composite, odd, even. We are given the probability of Prime number only. Insufficient.

Considering both:
The question asked for odd or prime. An Odd number can be prime and Odd too. So, the events are mutually inclusive. Thus we will multiply each probability. \(\frac{1}{6}\)*\(\frac{1}{3}\); Sufficient.

The answer C.
_________________
Collections:-
PSof OG solved by GC members: http://gmatclub.com/forum/collection-ps-with-solution-from-gmatclub-110005.html
DS of OG solved by GC members: http://gmatclub.com/forum/collection-ds-with-solution-from-gmatclub-110004.html
100 GMAT PREP Quantitative collection http://gmatclub.com/forum/gmat-prep-problem-collections-114358.html
Collections of work/rate problems with solutions http://gmatclub.com/forum/collections-of-work-rate-problem-with-solutions-118919.html
Mixture problems in a file with best solutions: http://gmatclub.com/forum/mixture-problems-with-best-and-easy-solutions-all-together-124644.html
Signature Read More
avatar
G
CEdward
SVP
SVP
Joined: 11 Aug 2020
Posts: 1753
Re: If a number is selected at random from a set of 6 distinct integers [#permalink] New post  10 Feb 2021, 19:47
P(odd or prime) = P(odd) + P(prime)

St1 - P(odd) = 1/6
Case 1: 1,4,6,8,10,12
Case 2: 2,3,6,8,10,12

P(odd or prime) = 1/6 in Case 1
P(odd or prime) = 1/3 in Case 2

Insufficient.

St2 - P(prime) = 1/3
Case 1: 1,3,6 ---> P(odd or prime) = 2/3
Case 2: 3,27,6 ---> P(odd or prime) = 1/3

Combined: Sufficient.
Answer is C.
_________________
"Do not pray for an easy life, pray for the strength to endure a difficult one." - Bruce Lee
Signature Read More
GMAT Club Bot
gmatclubot
Re: If a number is selected at random from a set of 6 distinct integers [#permalink]
10 Feb 2021, 19:47
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderators:
chetan2u
Math Expert
9813 posts
Bunuel
Math Expert
74514 posts
GMATBusters
Retired Moderator
1991 posts
nick1816
DS Forum Moderator
2266 posts

cron

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

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions