Thread: 2 probability questions

a lot of Thank you ...

Originally Posted by Narek

a lot of Thank you ...

As to the first: look at the probabilities of the complements:
P(U\E) = ???
P(U\F) = ???
and then look at P(U\(E n F)).

(where U is the "universe", i.e., all events).

As to the second: does it really matter which birthday person1 has? So, say it's January 13. Then look at the birthday of person2.

Refer to the link below, you will be able to solve the 2nd problem.

Birthday problem - Wikipedia, the free encyclopedia

I dont get the point .... can you solve it?

Originally Posted by Narek

I dont get the point .... can you solve it?

Try first: what's the probability that E does not occur, i.e. P(U \ E) ?
Likewise, the probability that F does not occur?

What's the sum of those?

What has that to do with the probability that (E n F) does not occur?

we dont know what day is for the first person, so we consider it as 1st january. and now we say, the probability of the second person having the same birthday is :

P= 1 / 366

__________________________________________________ ________

is this True???? thank you

Originally Posted by Narek

we dont know what day is for the first person, so we consider it as 1st january. and now we say, the probability of the second person having the same birthday is :

P= 1 / 366

__________________________________________________ ________

is this True???? thank you

Yes, that's correct.

for the first one, no matter how hard I try, I dont understand the concept ... I need to see the solution, please

any suggestion??? any guide?

Originally Posted by Narek

any suggestion??? any guide?

CB