How many people in a group would you expect to have the same birthday?

[Procrastinate]

In poker, you are normally dealt a hand of 5 cards. A flush has all cards of the same suit.
From 2000 hands, how many flushes would you expect?P(flushes from 2000 hands) = 12/51*11/50*10/49*9/48*2000=3.9616 (4) but the textbook says 3.24 (3)

Did I do something wrong?

A group of 40 people are surprised to find that 2 people have the same birthday. What is the probability that each person has their birthday on a different day?


Tried 38/364*37/363*36/362...but I just don't think that it was meant to be that long. Could someone please give me a hint on this question?

 

[Dick]

In poker, you are normally dealt a hand of 5 cards. A flush has all cards of the same suit.
From 2000 hands, how many flushes would you expect?P(flushes from 2000 hands) = 12/51*11/50*10/49*9/48*2000=3.9616 (4) but the textbook says 3.24 (3)

Did I do something wrong?

A group of 40 people are surprised to find that 2 people have the same birthday. What is the probability that each person has their birthday on a different day?


Tried 38/364*37/363*36/362...but I just don't think that it was meant to be that long. Could someone please give me a hint on this question?

Your answer for the first one looks correct to me. The second one doesn't look right at all. You do have to multiply a lot of numbers to get the answer for 40 people. But those aren't the right numbers.