amelia sets her CD player to randomly select songs from the 4 CD's she has loaded. Disc A has 8 songs, disc B has 10 songs, disc C has 7 songs, and disc D has 12 songs.
what is the probability that the first song she hears is from disc C?

Question

amelia sets her CD player to randomly select songs from the 4 CD's she has loaded. Disc A has 8 songs, disc B has 10 songs, disc C has 7 songs, and disc D has 12 songs.
what is the probability that the first song she hears is from disc C?

anonymous · Answer

@Directrix

directrix · Answer

what is the probability that the first song she hears is from disc C?
=======================

Well, there are 4 discs in the player. I think each disc is equally likely to be selected.
And, I think that the number of songs per disk does not matter.

But, I need someone else on OS to read the question and see what he or she thinks about it.

anonymous · Answer

hmmm let me see

anonymous · Answer

@thesmartone

directrix · Answer

It seems that we are selecting discs and not songs. 
Four discs and we want one of them which would make me think the probabillity
would be 1/4.

I would like to hear what @kropot72 has to say but he will not be on until later tonight.

anonymous · Answer

well its an assignment and once i leave it then i cant finish it

anonymous · Answer

and @TheSmartOne  is online i just dont know why he isnt coming

directrix · Answer

For the first song Amelia hears to be from disc C, then disc C would have to be chosen first. So, I am going with 1/4.

anonymous · Answer

well, lets see what thesmartone has to say

directrix · Answer

Another approach would be to add all the songs on all four discs: 8 + 10 + 7 + 12

Of those, 7 are on disc C

thesmartone · Answer

Hmm. I really don't know. It sounds confusing..
@Jhannybean @Nnesha Want to try this problem?

anonymous · Answer

geez......

directrix · Answer

7/( 8 + 10 + 7 + 12)     (The problem is poorly written.)

thesmartone · Answer

^ that was what I was thinking.

directrix · Answer

I think the problem writer was thinking that also. So, let's go with it.

thesmartone · Answer

Maybe @iambatman can save the day. :)

directrix · Answer

Not knowing the selection process of this machine is confusing.

anonymous · Answer

well i cant fail this assignment -.-

directrix · Answer

Understood.

thesmartone · Answer

I wonder if it has to do with permutations and combinations..

directrix · Answer

Looking at the question again:  >>  randomly select songs from the 4 CDs

I am convinced that the answer is 7/37 --> 7 songs on disc C and 37 total songs on the 4 discs.  @mcnabkt

anonymous · Answer

oh okay so how do we solve it?

directrix · Answer

Perhaps one of the onlookers will post an idea.

anonymous · Answer

-.-

anonymous · Answer

|dw:1421011357853:dw|

anonymous · Answer

so , the first song is from CD# C
|dw:1421011582872:dw|
means we are picking one out of 4
p(first song from C )=1/4