Math Combination Question

[Dublin08]

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

[Frankenstein]

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.

[saketk]

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)