Wednesday

April 23, 2014

April 23, 2014

Posted by **John** on Monday, October 1, 2012 at 5:35am.

bum that lets you choose any 10 songs from their song library for 9:99. ComboAlbum's advertising

says their song catalogue is so large there are over 10; 000; 000 different song combinations available

for download.

1.What is the minimum size of their song catalog if this claim is true?

2.If the song catalogue had the number of songs found in the previous part, but you

could download combinations of 5 songs for 4:99, how many different combinations of 5 songs would

there be?

3.If for 2:99 ComboAlbum will sell you a randomly selected combination of 10 songs,

what is the probability that your favorite 5 songs in the song library are among the 10 selected.

Again, use the total number of songs found in the rest part.

- Math -
**Reiny**, Monday, October 1, 2012 at 7:46amlet the number of songs be n

C(n,10) > 10 000 000

n!/(10!(n-10)) > 10 000 000

By trial and error, using my C(n,r) key on my calculator

C(25,10) = 3 268 760

C(26,10) = 5 311 735

C(27,10) = 8 436 285

C(28,10) = 13 123 110

1. So they must have at least 28 songs, (not very impressive)

2. Combinations of 5 from those 28

= C(28,5) = 98280

3. prob --- we need 5 of your favourite 5 plus 5 of the remaining 23

prob = C(5,5) x C(23,5)/C(28,10) = .002564

- Math -
**John**, Monday, October 1, 2012 at 1:25pmThank you!

**Related Questions**

English - I have a few last doubts. Thank yo very much for your corrections. 1)...

writing I - Can you please give me few examples of metaphors and similes about ...

Math - Amayor has a friend in publishing who tells him they have just published ...

music -year 8 - i`m doing a school project in music about buddy holly. i need ...

Health (Ms. Sue) - Your friend tells you that she heard on the radio that HIV ...

Health (Ms. Sue) - Your friend tells you, "My boyfriend is a star athlete. He ...

Biology - A friend tells you that because he has just recovered from a cold, he ...

English - Can you help me check these sentences, please? Thank you. I need to ...

Music - 1. How did the music business change in the early 1970s? 2. In what ways...

country report - Waht kind of music do they listen to in Thailand? I'm doing a ...