Question

A student club has 20 members. How many ways can the club choose a President, Secretary, and Treasurer?

Answer 1

You have 3 slots to fill

There are 20 ways to fill slot 1
There are 19 ways to fill slot 2 (you can have anyone fill more than one slot)
There are 18 ways to fill slot 3

Answer 2

multiply out these numbers to get your answer

Answer 3

alternatively you can use the formula

n P r = (n!)/((n-r)!)

but you are effectively doing the same thing and you'll get the same answer

Answer 4

Soo it's 6840?

Answer 5

yep

Answer 6

you are correct

Answer 7

Ohhh... Thanks :) Can you help me with one more please? :)

Answer 8

sure

Answer 9

P(8, 5) =
a. 40,320
b. 1,680
c. 6,720

I have no idea what P(8,5) means :p

Answer 10

P(n,r) is another way to write n P r

it's just different notation

Answer 11

so

P(n,r) = (n!)/((n-r)!)

P(8,5) = (8!)/((8-5)!)

P(8,5) = ??

Answer 12

btw, P(8,5) means that you now have 8 candidates and 5 slots

Answer 13

and you want to count how many ways there are to fill those 5 slots (where order matters)

Answer 14

So my answer is c?

Answer 15

yep you are correct, nice work

Answer 16

Thanks :)

Answer 17

you're welcome