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

It is currently 17 Aug 2018, 23:47

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.

Close

Request Expert Reply

Confirm Cancel

How many different ways are there to arrange a group of 3 adults and 4

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47978
How many different ways are there to arrange a group of 3 adults and 4  [#permalink]

Show Tags

New post 13 Dec 2016, 06:49
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

88% (00:57) correct 12% (00:54) wrong based on 137 sessions

HideShow timer Statistics

How many different ways are there to arrange a group of 3 adults and 4 children in 7 seats if adults must have the first, third, and 7 seats?

A. 12
B. 144
C. 288
D. 1,400
E. 5,040

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | 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

Senior Manager
Senior Manager
avatar
B
Joined: 13 Oct 2016
Posts: 367
GPA: 3.98
Re: How many different ways are there to arrange a group of 3 adults and 4  [#permalink]

Show Tags

New post 13 Dec 2016, 07:56
There are 3 adults that should be seated on three particular seats and 4 children on the rest four. Adults and children cannot switch places with each other, only among themselves

Hence: \(3!*4! = 6*24 = 144\)

Answer B
Intern
Intern
avatar
B
Joined: 12 Feb 2017
Posts: 4
How many different ways are there to arrange a group of 3 adults and 4  [#permalink]

Show Tags

New post 10 Dec 2017, 07:04
the adults have to be in 1 3 and 7th place , therefore : A*c*A*c*c*c*A
so it will be 3 x C x 2 x C x C x C x 1

now the children taking remaining places will be
3 x 4 x 2 x 3 x 2 x 1 x 1 = 144
Intern
Intern
avatar
Joined: 10 Dec 2017
Posts: 3
Re: How many different ways are there to arrange a group of 3 adults and 4  [#permalink]

Show Tags

New post 10 Dec 2017, 07:58
Bunuel wrote:
How many different ways are there to arrange a group of 3 adults and 4 children in 7 seats if adults must have the first, third, and 7 seats?

A. 12
B. 144
C. 288
D. 1,400
E. 5,040



Answer: 3 adults can be seated in 1st, 3rd and 7 th position in 3! ways. The remaining 4 positions are occupied by the remaining 4 people in 4! ways. Hence the total number of seating arrangements are 3!*4! = 144 ways.

Sneha Tatavarthy
Math Facililator
International Baccalaureate
_________________

Regards,
Sneha Tatavarthy
Math Facilitator
International Baccalaureate

EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 12189
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: How many different ways are there to arrange a group of 3 adults and 4  [#permalink]

Show Tags

New post 04 Jan 2018, 15:37
Hi All,

We're asked to arrange a group of 3 adults and 4 children in 7 seats with adults in the first, third, and seventh seats. We're asked for the number of arrangements possible. This question is a variation on a standard Permutation question. To solve it, we have to go from space to space and keep track of the 'options' available for each (noting that once we place a person, there is one fewer person available for the next equivalent spot).

For the 1st spot, there are 3 options
For the 2nd spot, there are 4 options
For the 3rd spot, there are 2 options
For the 4th spot, there are 3 options
For the 5th spot, there are 2 options
For the 6th spot, there are 1 options
For the 7th spot, there are 1 options

Total arrangements = (3)(4)(2)(3)(2)(1)(1) = 144 possible arrangments

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Re: How many different ways are there to arrange a group of 3 adults and 4 &nbs [#permalink] 04 Jan 2018, 15:37
Display posts from previous: Sort by

How many different ways are there to arrange a group of 3 adults and 4

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

Events & Promotions

PREV
NEXT


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

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®.