Please show the steps/working so I'll be able to understand how it works. Thank you!

11) A company needs 4 volunteers to organize their annual New Years Eve party. Each of the volunteers will have a different roll: one will create and distribute the invitations, another will select and order the food, the third will be in charge of selecting, securing and setting up the venue, and the last will be in charge of break down and clean up. How many different volunteer groups can be formed if the company has 51 employees