Question

How many different 12-member juries can be chosen from a pool of 40 people?

I really can't understand this.

Answer 1

40C12?

Answer 2

And : \(\large ^n C_r = \cfrac{n!}{r! (n-r)!} \)

Answer 3

@Haruhi , can you solve it now?

Answer 4

not really. I've been trying to solve it that way all this time. I'm getting weird results.

Answer 5

From
\[\large ^n C_r = \cfrac{n!}{r! (n-r)!} = \frac{40!}{12!(40-12)!} = \frac{40 \times 39 \times 38 \times...}{(12 \times 11 \times 10 \times ...)(28 \times 27 \times 26 \times ...)}\]

Answer 6

Or just use a calculator

Answer 7

What do you get?

Answer 8

I get 1.5186643e+48 (whatever that means) and my options are

a) 3,586,853,480
b) 4,586,853,480
c) 5,586,853,480
d) 6,586,853,480

Answer 9

Lol you should get 5,586,853,480 check your calculator

Answer 10

type "calculate 40 choose 12" into google

Answer 11

Ahh

Answer 12

it will take

"40 choose 12"

and give the answer

Answer 13

I think we don't have Google in the exam!?

Answer 14

Ok..... still confused. How can a calculator be wrong lol what the hell am I doing

Answer 15

Try:\[\frac{40!}{(12!(40-12)!)} \]

Answer 16

That is wrong all of you I think its 12 times 40 its simple probability i think

Answer 17

No nevermind

Answer 18

Its c

Answer 19

It's the right answer, yeah. But it's damn confusing having to work with numbers like 815,915,279,999,999,744,392,488,672,368,848,648,400,776,424,296 -_- so I must've made a mistake at some point.

Answer 20

please dont say dam on a post there are 7th graders in geometry and algebra 2 like me who don't like that

Answer 21

ok... >_>

Answer 22

What is that supposed to mean

Answer 23

weirdos