A musician has 5 songs she can play at an open mic night

Question

How many different ways she can play 2 of them?

 

A) 10

B) 20

Answer 1

okay, this question lacks some information.

 

i see three cases depending on your definition of playing a music set...

 

case 1:

two songs played, not caring about which was first or second on set

choose(5,2) = 10 ways

answer -> A 10

 

case 2:

two songs played, keeping a list of order in which the set went down

permute(5,2) = 20 ways

answer -> B 20

 

case 3:

having only options A or B suppose that the musician cannot play the same song twice

5*5 = 25 different ways!

 

mathematicians love to quibble about this stuff :)