Mike D. answered • 5d

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Talita

It's possible to choose from 21 people as it is you and 20 of your friends.

PR can be chosen in 21 ways.

VP can then be chosen in 20 ways (as one person has become PR)

CFO then can be chosen in 19 ways

So you can choose the combination in 21 x 20 x 19 = 7980 ways. This is the same as 21 P 3

Mike