Question

I need help with discrete math question

Answer 1

well what is it?

Answer 2

I already don't like this question.

Answer 3

its different because its non zero size and president and treasurer can be the same person

Answer 4

12 choices for the first job, and 12 for the second
multiply

Answer 5

@satellite73 i dont get what u mean can u explain with a sample example or something

Answer 6

there are 12 people right?

Answer 7

any of the 12 can be president, and any of the 12 can be treasurer
by the counting principle, the number of ways to do this is \(12\times 12\)

Answer 8

_(12 C 1)
__ (12 C 1)(11 C 1)+(12 C 2) (10 C 2)

Answer 9

this is how i approached this question for 3 seats it would be
___ 12 C 1 x 11 C 3 + 12 C 2 x 10 C 1

Answer 10

@hahd
It is not as complicated as you write above

just look at @satellite73 's last answer

12 options for each post....

Answer 11

it doesnt look that simple since its growing and for each 12 option theres a repetitive case...

Answer 12

Yeah @hahd is right, 144 isn't the answer here.

Answer 13

I interpret the question as saying there are exactly 2 posts - but they may be the same person

Answer 14

You're forming nonzero size committees. That's only part of the question @MrNood

Answer 15

^

Answer 16

@Empty does my approach look fine I kinda feel like there should be an easier way than doing all 12 cases

Answer 17

http://www.johndcook.com/blog/select_with_replacement/

Answer 18

Luckily the answer doesn't appear to be far off, the way I'm thinking about it is to modify satellite's answer, I haven't looked at your thing and I'm not a hundred percent sure this is correct:

So what he said was if we have 12 people there are 12x12 ways to pick the president and treasurer. We still want to consider all the cases from 1 to 11 though, so we can just add:

1x1+2x2+...+12x12.

And I think that'll do it

Answer 19

is there a way to justify your answer

Answer 20

cause i honestly have trouble seeing it how u are 1x1 makes no sense to me
as when there is one seat u should have 12 options of putting people in it

Answer 21

Ahhh yeah ok so this isn't completely correct I left something out I realized. So if you pick only one person then there's only 1 way to pick president and 1 way to pick treasurer. so 1x1 is the number of ways to make a 1 person committee, after choosing one person. But there are 12 different ways to pick one person, so we have to multiply this by 12C1.

But how many ways are there to make 2 person committee? 2 ways to pick the president and 2 ways to pick the treasurer and now we have 12C2 to multiply this by.

So here's kinda where I am right now, I think this works out.

Answer 22

FWIW- the formula in the link above gives an answer of 78

(I only give this for you to compare your workings against - not as a 'direct answer')

Answer 23

jk guys i was reading the question wrong Lol...

Answer 24

thanks for all your help guys