B is for . . .

Do you hate math? Know someone who is great at math? Usually it's one or the other. This month I'm posting some Mad-Cool-Math Nuggets. Maybe it'll make you think twice about numbers.


Image courtesy: 4rank

B is for The Birthday Paradox.

They say it's your birthday! It's my birthday too, yeah!

There are around 7 billion people on the planet and only 366 (including Feb. 29) days in the year. Even if you can't do the math, obviously you're sharing your birthday with lots and lots of people. Still, would it surprise you to know that in a group of just 23 randomly chosen folks, the probability that two share a birthday is

(a) 10%
(b) 20%
(c) 30%
(d) 40%
(e) 50%

Answer: e

That's right. Are you a writer? Go ahead those two star-crossed lovers who meet in a bar the same birthday.

Want to know why? I'll send you here for a YouTube Video to provide a general idea and here for an article on actually calculating the odds.

There are birthdays that are more popular than others. For Americans between 14 and 40, the most common is September 16. In fact, September is the biggest birthday month (which means Christmas time is the biggest . . . ah hem, time for something else). Check out this chart.

When I went to Flickr to pick out an image for this blog, my top choice, as seen above, was snapped on my birthday! Maybe I shouldn't be surprised.

What month is your birthday? Have you heard about the Birthday Paradox? Do you know who sings The Birthday Song with the lyrics above?