Find all School-related info fast with the new School-Specific MBA Forum

It is currently 25 Sep 2016, 22:41
GMAT Club 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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Two integers will be randomly selected from the sets above,

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

Hide Tags

1 KUDOS received
Manager
Manager
avatar
Joined: 02 Dec 2012
Posts: 178
Followers: 4

Kudos [?]: 1978 [1] , given: 0

Two integers will be randomly selected from the sets above, [#permalink]

Show Tags

New post 02 Dec 2012, 07:51
1
This post received
KUDOS
8
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

78% (02:10) correct 22% (01:33) wrong based on 657 sessions

HideShow timer Statistics

A = {2, 3, 4, 5}
B = {4, 5, 6, 7, 8}

Two integers will be randomly selected from the sets above, one integer from set A and one integer from set B. What is the probability that the sum of the two integers will equal 9 ?

(A) 0.15
(B) 0.20
(C) 0.25
(D) 0.30
(E) 0.33
[Reveal] Spoiler: OA
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34830
Followers: 6482

Kudos [?]: 82625 [0], given: 10108

Re: Two integers will be randomly selected from the sets above, [#permalink]

Show Tags

New post 02 Dec 2012, 07:52
Expert's post
5
This post was
BOOKMARKED
Walkabout wrote:
A = {2, 3, 4, 5}
B = {4, 5, 6, 7, 8}

Two integers will be randomly selected from the sets above, one integer from set A and one integer from set B. What is the probability that the sum of the two integers will equal 9 ?

(A) 0.15
(B) 0.20
(C) 0.25
(D) 0.30
(E) 0.33


The total number of pairs possible is 4*5=20. Out of these 20 pairs only 4 sum up to 9: (2, 7); (3, 6), (4, 5) and (5, 4). The probability thus is 4/20=0.2.

Answer: B.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

4 KUDOS received
Intern
Intern
avatar
Joined: 18 Feb 2012
Posts: 12
Followers: 0

Kudos [?]: 4 [4] , given: 2

Re: Two integers will be randomly selected from the sets above, [#permalink]

Show Tags

New post 02 Dec 2012, 18:51
4
This post received
KUDOS
How about this line of thought:

I pick a number from Set A. No matter which number I pick, my chance of chosing the right number (which gives A+B = 9) in Set B will be 1/5.

Therefore 1/5 = 0.20 => B
Intern
Intern
avatar
Joined: 15 Oct 2013
Posts: 14
Concentration: Marketing, Finance
Schools: McCombs '16
Followers: 0

Kudos [?]: 2 [0], given: 15

probability sum is equal to 9 [#permalink]

Show Tags

New post 15 Feb 2014, 06:29
hi
the question is as below

a={2,3,4,5}
b={4,5,6,7,8}

Two integers will randomly selected from the sets above, one integer from set A and one integer from set B. what is the probability that the sum of the two integers will equal 9.
a)0.15
b)0.20
c)0.25
d)0.30
e)0.33

I want to understand how will we calculate the total outcomes.
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34830
Followers: 6482

Kudos [?]: 82625 [0], given: 10108

Re: probability sum is equal to 9 [#permalink]

Show Tags

New post 15 Feb 2014, 06:33
mightymk wrote:
hi
the question is as below

a={2,3,4,5}
b={4,5,6,7,8}

Two integers will randomly selected from the sets above, one integer from set A and one integer from set B. what is the probability that the sum of the two integers will equal 9.
a)0.15
b)0.20
c)0.25
d)0.30
e)0.33

I want to understand how will we calculate the total outcomes.


Merging similar topics. Please refer to the solutions above.

P.S. Please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to rules 1 and 3. Thank you.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Manager
Manager
avatar
Joined: 07 Apr 2014
Posts: 147
Followers: 1

Kudos [?]: 19 [0], given: 81

Re: Two integers will be randomly selected from the sets above, [#permalink]

Show Tags

New post 11 Sep 2014, 01:54
Walkabout wrote:
A = {2, 3, 4, 5}
B = {4, 5, 6, 7, 8}

Two integers will be randomly selected from the sets above, one integer from set A and one integer from set B. What is the probability that the sum of the two integers will equal 9 ?

(A) 0.15
(B) 0.20
(C) 0.25
(D) 0.30
(E) 0.33



total possibility -- 4c1 *5c1

possible stuff: (2,7), (3,6), (4,5),(5,4)= 4

4/20= 1/5= 0.2
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 11677
Followers: 527

Kudos [?]: 143 [0], given: 0

Premium Member
Re: Two integers will be randomly selected from the sets above, [#permalink]

Show Tags

New post 06 Nov 2015, 19:29
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Intern
Intern
avatar
Joined: 23 Mar 2016
Posts: 38
Schools: Tulane '18 (M)
Followers: 0

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

Re: Two integers will be randomly selected from the sets above, [#permalink]

Show Tags

New post 02 May 2016, 15:23
Probability of A (any number) AND B(4 of 5).
We don't need to calculate each and every probability, rather the overall. But let's go the long way to see the theory behind the easy way.

A = { 2, 3, 4, 5}
B = {4, 5, 6, 7, 8}

If we choose 2 from A, the only way we can get a sum of 9 is if we choose 7 from B.

2 from A = .25 probability of occurring (1/4)
7 from B = .20 probability of occurring (1/5)
(1/4)*(1/5) = 1/20
If you do this for each number in A, you get the same outcome, 1/20
add all of these up, and you get 1/20 + 1/20 + 1/20 + 1/20 = 4/20 = 4/20(5) = 20/100 = .2 to get the sum of 9 when choosing a number from A and its corresponding "match" from B (3+5)(2+7)(4+5)(5+4)

Now to take the easy route.
For any number in A, you have a 4/4 chance of picking a number (100% strike rate)
For any number in B, you have a 4/5 chance of picking a number (80% strike rate)
4/4 * 4/5 = 16/20 chance of getting any addition answer, therefore a 4/20 chance of getting 9 as a sum = 20%, .2
1 KUDOS received
Manager
Manager
User avatar
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 239
Followers: 11

Kudos [?]: 51 [1] , given: 2

Re: Two integers will be randomly selected from the sets above, [#permalink]

Show Tags

New post 03 May 2016, 05:46
1
This post received
KUDOS
Walkabout wrote:
A = {2, 3, 4, 5}
B = {4, 5, 6, 7, 8}

Two integers will be randomly selected from the sets above, one integer from set A and one integer from set B. What is the probability that the sum of the two integers will equal 9 ?

(A) 0.15
(B) 0.20
(C) 0.25
(D) 0.30
(E) 0.33


Solution:

To determine the probability that the sum of the two integers will equal 9, we must first recognize that probability = (favorable outcomes)/(total outcomes).

Let’s first determine the total number of outcomes. We have 4 numbers in set A, and 5 in set B, and since we are selecting 1 number from each set, the total number of outcomes is 4 x 5 = 20.

For our favorable outcomes, we need to determine the number of ways we can get a number from set A and a number from set B to sum to 9. We are selecting from the following two sets:

A = {2, 3, 4, 5}

B = {4, 5, 6, 7, 8}

We will denote the first number as from set A and the second from set B. Here are the pairings that yield a sum of 9:

2,7
3,6
4,5
5,4

We see that there are 4 favorable outcomes. Thus, our probability is 4/20 = 0.25, Answer C.
_________________

Image
Jeffrey Miller
Jeffrey Miller
Head of GMAT Instruction

Re: Two integers will be randomly selected from the sets above,   [#permalink] 03 May 2016, 05:46
    Similar topics Author Replies Last post
Similar
Topics:
8 Experts publish their posts in the topic Two integers will be randomly selected from sets A and B 2013gmat 7 24 Oct 2012, 22:05
7 Experts publish their posts in the topic If three numbers are randomly selected from set A without shrive555 7 28 Dec 2010, 10:02
6 Experts publish their posts in the topic If two different numbers are randomly selected from set { 1, rxs0005 8 23 Jul 2010, 08:52
23 Experts publish their posts in the topic Two integers will be randomly selected from the sets above vermatanya 20 17 Jan 2008, 14:50
15 Experts publish their posts in the topic If an integer is to be randomly selected from set M above marcodonzelli 12 12 Jan 2008, 05:29
Display posts from previous: Sort by

Two integers will be randomly selected from the sets above,

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


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.