Cool math fact

Can you tell me a cool math fact?

@ChristmasHums said in #1:

in a group of 23 with randomly chosen people, there's 50% chance that 2 people share the same birthday..

If you are in a group of 23 (including yourself) randomly chosen people, there's a 6.1% chance that someone has the same birthday as you (assuming nobody is born on Feb 29th).

How many people would you need for there to be a 50% chance (or more) that someone has the same birthday as you?

@CalbernandHowbe said in #3:

How many people would you need for there to be a 50% chance (or more) that someone has the same birthday as you?
255

Yes. But if your birthday is February 29th, you would need 1013 people in a room for there to be at least a 50% chance someone has the same birthday as you (ignoring years like 1900)

Your Braincells+1=1

111,111,111 x 111,111,111 = 12,345,678,987,654,321.

That's an pretty easy fact and even though I know how it works it's still intriguing.
Do any of you know the 1089 Process?

0 is imaginary.
There are 0 fishes.something that doesnt exist cant be valued but with number 0 its possible.it means there is no fishes

@ajfang said in #7:

111,111,111 x 111,111,111 = 12,345,678,987,654,321.

That's an pretty easy fact and even though I know how it works it's still intriguing.
Do any of you know the 1089 Process?
What's that?

Graph for
sqrt(cos(x))cos(300x)+sqrt(abs(x))-0.7)(4-x*x)^0.01, sqrt(6-x^2), -sqrt(6-x^2) from -4.5 to 4.5
will be a heart