Question 673995
1) The songs can be played in any order:

    No of ways the 9 songs can be played = 9! = 362880

Explanation: the 1st song can be chosen from any of the 9 songs, the 2nd played song can be chosen from the remanining 8 songs, the 3rd played song can be chosen from the remaining 6 songs, the 5th played song can be chosen from the remaining 5 songs, the 6th played song can be chosen from the remaining 4 songs, the 7th played song can be chosen from the remaining 3 songs, the 8th played song can be chosen from the remaining 2 songs and the 9th played song can be chosen from the remaining 1 song. Hence the no of ways = 9*8*7*....2*1 =9!

2) The first song must be a slow song and the last song must be a slow song.

No of ways the 1st song can be chosen = 5 (as there are 5 slow songs)
No of ways the 9th song can be chosen = 4 (as there are 4 remaining slow songs left) 

Having chosen the 1st and 9th, the songs 2 thru 8 can be chosen in 7! ways

Total no of ways = 7!*5*4 = 100800 ways

3) The first two songs must be fast songs.

No of ways to select 1st song = 4 (as there are 4 fast songs)
No of ways to select 2nd song = 3 (as there are remaining 3 fast songs)

Having chosen 1st and 2nd song, the songs 3 thru 9 can be chosen in 7! ways

Total no of ways = 7!*4*3 = 60480