Suppose you just purchased a digital music player and have put 13 tracks on it. After listening to them you decide that you like 2 of the songs. With the random feature on your player, each of the 13 songs is played once in random order. Find the probability that among the first two songs played (a) You like both of them. Would this be unusual? (b) You like neither of them. (c) You like exactly one of them. (d) Redo (a)-(c) if a song can be replayed before all 13 songs are played.
You like 2 of 13 songs.
a) Getting both of the songs (no repeats): (2/13) x (1/12) =
b) Getting neither song (no repeats): (11/13) x (10/12) =
c) Getting one of them, in either order (no repeats): (2/13) x (11/12) + (11/13) x (2/12) =
a) Getting both of the songs (repeats allowed): (2/13) x (2/13) =
b) Getting neither song (repeats allowed): (11/13) x (11/13) =
c) Getting one of them, in either order (repeats allowed): (2/13) x (11/12) + (11/13) x (2/12) =