BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Permutation and Combination Problem

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 202
Joined: Sun Sep 08, 2013 11:51 am
Thanked: 3 times
Followed by:2 members

Permutation and Combination Problem

by sukhman » Tue Sep 10, 2013 2:47 am
A group of 5 students bought movie tickets in one row next to each other. If Bob and Lisa are in this group,what is the number of ways of seating if both of them will sit next to only one other student from the group? Answer 3 ! × 2 !
Top
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 234
Joined: Tue Jul 16, 2013 9:00 am
Location: West Virginia
Thanked: 9 times

by Java_85 » Tue Sep 10, 2013 11:45 am
Imagine there are 5 sits--> _ _ _ _ _
If bob and lisa will sit next to only one other student from the group, then each of them should be sitting in one end of row i.e. Bob _ _ _ Lisa or Lisa _ _ _ Bob ==>
Answer = 2(the mentioned states) * 3!(for the three empty spots in between). ==> 2! * 3!
Top
Post new topic Post Reply
• Page 1 of 1