Question

in how many ways can 15 people be divided into two groups, one group with 10 and the other with 5 people?

Answer 1

um..two? xD

Answer 2

2

Answer 3

you are dealing with a nCr ... have you ever heard of that?

Answer 4

yeah combinations!

Answer 5

one

Answer 6

15C(10) * 5C5

Answer 7

(where order doen't matter, as opposed to nPr, in thing like password...)
Cool, so you get 15 people in 2 different groups
you can split them into 2 groups 10 and 5

I am not sure, is it nPr or nCr, the question doesn't really say.

Answer 8

I think it is combo because order doesn't really matter, right?

Answer 9

just forget about five people....
say the following.

I am choosing people 10 people out of 15

so either
15 nCr 10 or
15 nPr 10

I think the question is actually going on the second, the nPr.

More help?

Answer 10

No it is nCr...

why forget the 5 people? because when i choose 10, the 5 people are chosen already

again, yes it is nCr, my bad.

Answer 11

Oh! I see! So all I need to do is plug in 15C10 correct?

Answer 12

http://www.calculatorsoup.com/calculators/discretemathematics/combinations.php

check there to see that what I said wastrue,

notice that 15 nCr 5= 15 nCr 10

Answer 13

@cherrygirl, @LifeIsADangerousGame, @mony01
Do you get why 3003 is the answer?

Answer 14

essay? (sorry....)

Answer 15

@mebs choosing 10 people for the big group automatically choose the 5 people that weren't chosen for the second group, so you only have to calculate one group

Answer 16

In this case yes, but some functions are going to be nPr

like a password combinations those are nPr, obviously, b/c the order matters....

Answer 17

you can plug in either 15 nCr 5 or 15 nCr 10

they both are the same... see my third comment?

Answer 18

@cherrygirl, can you tell me how old are you? i am 15.

Answer 19

@mebs, do you see how I did it?

Answer 20

if you guys need help, anything with trigonometric functions and below.

Answer 21

@cherrygirl are you getting any of this?

Answer 22

good bye! Main thing is, you know how to do those. i am sure you do!

Answer 23

Thank you guys! Sorry my computer shut down and this website wasn't working for a long time