Help Asap! I am having so much trouble with this subject and I have multiple problems! Please help! lol
so you have 23 students, 20 of which wont hold office
yes
So take 23 and set that to your combinations of 1st office
Now, take that number down to 22 and that is how many can hold 2nd office * 23.
combinations as in ncr=n!/((n-r)! r!) ????
Huh?
I don't know the equation.
lol okay. I think I have an idea of what to do. Still a little lost tho. lol
You now have the combinations for 1st and 2nd office.
So 23 *22
Now you want to multiply that by 21 for how many students can hold 3rd office.
@Pixel
Is that right?
10626
i believe so
Okay! Thank you!
ill help
ok
mmmmmmm
\[_{n}C _{k} = \frac{ n! }{ k! (n-k)! }\]
dam
Where, \[_{23}C _{3} = \frac{ 23! }{ 3! (20 - 3)! }\]
\(\color{#0cbb34}{\text{Originally Posted by}}\) @Shadow Where, \[_{23}C _{3} = \frac{ 23! }{ 3! (20 - 3)! }\] \(\color{#0cbb34}{\text{End of Quote}}\) Thanks!
(Missed a 23) Where, \[_{23}C _{3} = \frac{ 23! }{ 3! (23 - 3)! }\]
Think my mind was already thinking 20 lol
lollll I got it. lolll
But basically you get: \[\frac{ 23! }{ 3! \times 20! } \rightarrow \frac{ 23 \times 22 \times 21 \times 20! }{ 3! \times 20! }\]
Becoming: \[\frac{ 23 \times 22 \times 21 }{ 3 \times 2 \times 1} = 1771\]
Thank you! I have another problem posted if you're able to help on it! :D
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