A community for students. Sign up today!
Here's the question you clicked on:
 0 viewing
 3 years ago
Suppose there are 5 students in a class. What is the probability of having exactly 3 students who have the same birthday?
I am thinking I should have \[365 \times 365 \times 364 \times 363 \times 362\] and then divide all of it by 5. But it doesn't feel right.
What should I do to find out the probability?
 3 years ago
Suppose there are 5 students in a class. What is the probability of having exactly 3 students who have the same birthday? I am thinking I should have \[365 \times 365 \times 364 \times 363 \times 362\] and then divide all of it by 5. But it doesn't feel right. What should I do to find out the probability?

This Question is Closed

ash2326
 3 years ago
Best ResponseYou've already chosen the best response.2three students have b'day o same day, rest two will have on different days so no. of cases =365*364*363 total no. of cases =365*365*365*365*365 so probability=364*363/(365)^4

ash2326
 3 years ago
Best ResponseYou've already chosen the best response.2no of required cases =365*1*1*364*363

xEnOnn
 3 years ago
Best ResponseYou've already chosen the best response.0Why is it (365)^4 and not (365)^5?

ash2326
 3 years ago
Best ResponseYou've already chosen the best response.2one 365 got cancelled by the numerator's 365

xEnOnn
 3 years ago
Best ResponseYou've already chosen the best response.0oh i see.... Thank you so much! :)
Ask your own question
Ask a QuestionFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.