At a baby shower, 15 guests are in attendance and 4 of them are randomly selected to receive a door prize. If all 4 prizes are identical, in how many ways can the prizes be awarded?

Respuesta :

Answer:

1365

Step-by-step explanation:

We figure out combinations using this formula:    n!

                                                                              r!(n-r)!

n=15

r=4

So n!= 15x14x13x12x11x0x9x8x7x6x5x4x3x2x1

r! = 4x3x2x1 times 15-4!, which is 11! = 11x10x9x8x7x6x5x4x3x2x1

Put this together and you have 15x14x13x12/4x3x2x1=