Combinations of a shuffled deck of cards?
 

I saw a post on reddit about how many combinations of a shuffled deck of cards there are. This is unbelievable - but the numbers do make sense:

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A sum that could give Avogadro number envy.

Here's another cool math fact:

On a certain TV show about numbers and math, etc., the host had 150 people guess the number of jelly beans in a very large jar. Let's say there were 4,170 of them. (I forgot the exact number.) He had guesses ranging from 400 to 40,000. Pretty ridiculous guesses! But there were sensible guesses, as well.

Anyway, the host was trying to demonstrate how a large number of such guesses would zero in on the right number, no matter how far off some of them were. But even he was surprised when, after tallying all the guesses and taking the average, he came up with 4,174 jelly beans, only 4 off the true number. :eek:

The other day I went to a store that had a similar contest. I asked if I could look at the guesses that had been entered so far. He said no.

52! (That's factorial notation.)

There are 52 possibilities for the first card in the deck. There are 51 possibilities for the second card in the deck....all the way down to 1 possibility given the first 51 cards.

52x51x50.......x3x2x1 = 52!

I have heard the same thing about weight of an object. The average of a large number of guesses will be close.

This also applies to a fat person, the large number of guesses will be close. :o