Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 2512:30 AM EDT
-01:30 AM EDT
At one point, she believed GMAT wasn’t for her. After scoring 595, self-doubt crept in and she questioned her potential. But instead of quitting, she made the right strategic changes. The result? A remarkable comeback to 695. Check out how Saakshi did it.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
Vamshi8411
Joined: 24 Jul 2012
Last visit: 20 Oct 2013
Posts: 12
Given Kudos: 7
Schools: Schulich '16
GMAT 1: 610 Q49 V26
WE:Consulting (Consulting)
26 Jul 2012, 05:31
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
54% (01:08) correct
46%
(01:25)
wrong
based on 641
sessions
History
Date
Time
Result
Not Attempted Yet
In how many ways can a teacher in a kindergarten school arrange a group of 6 children (Susan, Karen, lei, Tim, joy and Zen) on 6 identical chairs in a straight line so that Susan is on the left of Tim?
A. 720
B. 360
C. 240
D. 120
E. 60
A. 720
B. 360
C. 240
D. 120
E. 60
21 Dec 2015, 11:05
Kudos
Bookmarks
Vamshi8411
Method-1:
Total ways in which 6 children can be arranged on 6 chairs = 6*5*4*3*2*1 = 6! = 720
But in half cases Susan will be left of Tim and in other half of cases Tim will be on left of Susan
i.e. Desired cases in which Susan is on the left of Tim = (1/2)*720 = 360
Method-2:
We have six vacant chairs _ _ _ _ _ _
out of which 2 have to be occupied by Tim and Susan, No. of ways of selecting chairs for Tim and Susan = 6C2 = 15
No. of ways of arranging Tim an Susan on selected chairs = 1 (Because Susan must be on the left of Tim)
Total ways of arranging 4 remaining children on 4 remaining chairs = 4*3*2*1 = 4! = 24
i.e. Total Arrangement = 6C2 * 1 * 4! = 15*1*24 = 360
Method-3:
Case 1: S _ _ _ _ _
Total ways of arranging Tim to the right of Susan = 5
Total ways of arranging Remaining 4 children = 4!
i.e. Total Arrangement in this case = 5*4!
Case 2: _ S _ _ _ _
Total ways of arranging Tim to the right of Susan = 4
Total ways of arranging Remaining 4 children = 4!
i.e. Total Arrangement in this case = 4*4!
Case 3: _ _ S _ _ _
Total ways of arranging Tim to the right of Susan = 3
Total ways of arranging Remaining 4 children = 4!
i.e. Total Arrangement in this case = 3*4!
Case 4: _ _ _ S _ _
Total ways of arranging Tim to the right of Susan = 2
Total ways of arranging Remaining 4 children = 4!
i.e. Total Arrangement in this case = 2*4!
Case 5: _ _ _ _ S _
Total ways of arranging Tim to the right of Susan = 1
Total ways of arranging Remaining 4 children = 4!
i.e. Total Arrangement in this case = 1*4!
Total Arrangements = 5*4!+5*4!+4*4!+3*4!+2*4!+1*4! = 4!(5+4+3+2+1) = 24*15 = 360
Answer: Option B
26 Jul 2012, 05:43
Kudos
Bookmarks
Vamshi8411
6 children can be arranged in 6! ways. Now, in half of these arrangements Susan will be on the left of Tim and in half she'l be on the right of Tim, so the answer is 6!/2=360.
Answer: B.
Similar questions to practice:
susan-john-daisy-tim-matt-and-kim-need-to-be-seated-in-130743.html
goldenrod-and-no-hope-are-in-a-horse-race-with-6-contestants-82214.html
in-how-many-different-ways-can-the-letters-a-a-b-91460.html
