I decided to make a CD with all with 8 of my 15 favorite math songs. How many different arrangements of the 8 songs are possible?

Answer 1

15C8 = 15!/8!7! = 15x14x13x12x11x10x9/7x6x5x4x3x2=32432400/5040 =6,435

unless orders matters

then it's permutations > combinations

15P8 = 15!/7!= 15x14x13z12x11x10x9x8 =259,459,200 different ways