## Shadowys Group Title Here's another fun one! Fifteen students are distributed to three classes. Anong them, three of them are special students. What are the probability that each class has only one special student? one year ago one year ago

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1. Algebraic! Group Title

$\frac{ (potato-1)! }{ potato!(potato-2)! }$

Potatoes!! lol

3. sauravshakya Group Title

3! * 3^12

Isn't that larger than 1?

5. sauravshakya Group Title

Oh sorry that was number of ways it can be done.

6. sauravshakya Group Title

(3! * 3^12)/3^15

The students can only be shuffled within their respective classrooms though...

8. sauravshakya Group Title

And that means?

that means that once a special occupies a classroom, the other students might lose that chance to go into that classroom for the the probability that one student goes into one classroom.

10. sauravshakya Group Title

What was wrong with the answer I gave?

your students were given three choices no matter the permutations of the three specials. however, in the case of two specials occupying two classrooms, they would only have one choice instead.

12. sauravshakya Group Title

First special student have 3 choices Second special student have 2 choices Third special student have one choices. And the rest students will have 3 choices.

yes. But in the case of 1-1-13 classroom arrangement, where the first two classes will have the two specials, the 12 students don't have this choice of entering the classroom.

14. sauravshakya Group Title

@Shadowys can u PLZ explain the question once again.

sorry~ ehheh Fifteen students, three among them are special. are distributed to three classes, and each class must contain only one special student, there is no limit on the number of students in the class except that all students must go into a class. What is the probability?

16. sauravshakya Group Title

Then, what is wrong with 3!*3^12/3^15

the students can be reshuffled in the classes without changing the class. Frankly saying, I got your answer when I first did it before I tried simplifying the question and testing it again. Hmm~I'll check with teacher again. It might be that he's wrong~

18. sauravshakya Group Title

@satellite73 PLZ check this.

19. satellite73 Group Title

i don't understand the question