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

Redeem

Math Combination Question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Tue Aug 23, 2011 8:25 am

Math Combination Question

by Dublin08 » Tue Aug 23, 2011 8:29 am
Can anyone help explain how to get the answer to this question

There are 12 x songs in a list and each student has to select 2 x favourite songs from this list, each song is selected 4 x times - how many students were asked to parttake in this exercise?

thanks
Top
Source: — Problem Solving |
Legendary Member
Posts: 1448
Joined: Tue May 17, 2011 9:55 am
Location: India
Thanked: 375 times
Followed by:53 members

by Frankenstein » Tue Aug 23, 2011 8:36 am
Hi,
There are 12x songs and each song is selected 4x times. So, total selections = 12x * 4x.
Each student selects 2x songs.
So, number of students = 12x * 4x/2x = 24x.
Cheers!

Things are not what they appear to be... nor are they otherwise
Top
Legendary Member
Posts: 608
Joined: Sun Jun 19, 2011 11:16 am
Thanked: 37 times
Followed by:8 members

by saketk » Wed Aug 24, 2011 9:09 am
Dublin08 wrote:Can anyone help explain how to get the answer to this question

There are 12 x songs in a list and each student has to select 2 x favourite songs from this list, each song is selected 4 x times - how many students were asked to parttake in this exercise?

thanks
To start with consider that out of 12 songs each student has to
Select 2 songs and every song can be selected only once. I am telling you this to ezxplain you the logic
Now if you want to find the number of people the simply multiply 12 by 1 and divide by 2. You will get 6 as the answer. Why this? Simply because a song selected once is out of next selection process. Now you just have to replicate this concept in the given question. Your answer will be 24 (6*4)
Top
Post new topic Post Reply
• Page 1 of 1