Recent GMAT Questions from the GMATprep CD.

This topic has expert replies
Source: — Problem Solving |

User avatar
Junior | Next Rank: 30 Posts
Posts: 14
Joined: Tue Jun 14, 2011 10:23 am

by fbgeoff » Tue Nov 01, 2011 10:04 am
Sorry about how little the image is. The answer shown is wrong. Needing help on how to solve this. Thanks

Legendary Member
Posts: 966
Joined: Sat Jan 02, 2010 8:06 am
Thanked: 230 times
Followed by:21 members

by shankar.ashwin » Tue Nov 01, 2011 10:08 am
You could search for the problems in the forum, most of them are discussed several times and a lot of experts have given some great solutions.
GMATPrep problems are one the most discussed problems in the forum.

User avatar
Legendary Member
Posts: 588
Joined: Sun Oct 16, 2011 9:42 am
Location: New Delhi, India
Thanked: 130 times
Followed by:9 members
GMAT Score:720

by rijul007 » Tue Nov 01, 2011 10:13 am
Total no of selections = 12*4 = 48
As each student selected 2,
Total no of students = 48/2 = 24

Option D

Legendary Member
Posts: 608
Joined: Sun Jun 19, 2011 11:16 am
Thanked: 37 times
Followed by:8 members

by saketk » Tue Nov 01, 2011 11:20 am
fbgeoff wrote:Sorry about how little the image is. The answer shown is wrong. Needing help on how to solve this. Thanks
You can solve this without any complex Math [ i.e. if you don't want PnC concepts here]

Suppose we have 6 pairs (2 *6 = 12 songs)

Let, first pair has 2 songs A and B. Since, we already know that each song is selected 4 times, you can assume that 'A' and 'B' were selected by 4 students. i.e. 1 pair is selected by 4 random students.

Now, that pair is out of next selection. we have 5 more pairs left. Just multiply 5 by 4.

Total = 20 + 4 [ of first selection ]

Your answer = [spoiler](24)[/spoiler]