I think there are 23 people. She entered the room after it already had 22. I don’t get why there’s a 50% chance that out of 365 days 2 should have the same birthday.
That might look a bit complicated, but it is kind of similar to the russian roulette with remixing...
Hidden:
For the russian roulette, we had 5/6 chances of survival at the first try, 5/6 * 5/6 for the second try,
5/6 * 5/6 * 5/6 for the third, etc...
Now for the birthday, we have 365/365 chances of not having the same birthday as anyone else for the first person (because there is only one person, only one birthday, no sharing).
The second person has a chance of 364/365 * 1 of not having the same birthday, since this person could pick from the 364 remaining days so as not to have the same birthday.
the third person has a chance of 363/365 of not having the same birthday as either of them, and together they have a chance of 363/365* 364/365* 365/365 that no-one shares birthdays.
So the 23rd person has a chance of 342/365 of not sharing a birthday with any of the other ones, and together they have a chance of 365*364*363*....* 343/36523 that no-one shares birthdays...
And if you calculate that, you get 49%, which means that the have a little over 50% chance to share a birthday...
If this was not clear enough, here is a youtube video...
That might look a bit complicated, but it is kind of similar to the russian roulette with remixing...
Hidden:
For the russian roulette, we had 5/6 chances of survival at the first try, 5/6 * 5/6 for the second try,
5/6 * 5/6 * 5/6 for the third, etc...
Now for the birthday, we have 365/365 chances of not having the same birthday as anyone else for the first person (because there is only one person, only one birthday, no sharing).
The second person has a chance of 364/365 * 1 of not having the same birthday, since this person could pick from the 364 remaining days so as not to have the same birthday.
the third person has a chance of 363/365 of not having the same birthday as either of them, and together they have a chance of 363/365* 364/365* 365/365 that no-one shares birthdays.
So the 23rd person has a chance of 342/365 of not sharing a birthday with any of the other ones, and together they have a chance of 365*364*363*....* 343/36523 that no-one shares birthdays...
And if you calculate that, you get 49%, which means that the have a little over 50% chance to share a birthday...
If this was not clear enough, here is a youtube video...
I spaced out after 20 seconds but thanks anyway
I’m afraid my brain is too sunny side upped at this point.
Ahhhhhhhhh. Now I got it. All you gotta do is say it with food and it will break through all sunny fried up barriers.
Yes I love love love math but when the mind is on overload it can’t concentrate as well as it did several decades ago
Keep em coming though.
Ahhhhhhhhh. Now I got it. All you gotta do is say it with food and it will break through all sunny fried up barriers.
Yes I love love love math but when the mind is on overload it can’t concentrate as well as it did several decades ago
Keep em coming though.
Still in Backgammon (sheshbesh)
You throw two dice.
You can count either the sum of the points on both dice, or each die separately:
What is the least probable number you can throw with two dice?
What is the most probable number you can throw with two dice?
