A girl has 50 disks she but she only wants to take 4 on a tr

A girl has 50 disks she but she only wants to take 4 on a trip. How many choices of 4 discs does she have? Once she\'s chosen the 4, in how many orders can she play them while on the trip?

Solution

choices of 4 discs = ⁵⁰C₄ = 50!/4!*46! = 47*48*49*50/24 =230300

No of orders she can play = 4*3*2*1 = 24