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# Confetti

## Question

If i toss 100 dollar bills from the top of a building ,what is the chance that more of them landing up side down on the ground?

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Assuming an equal chance of landing face up and landing face down...

P (face down >= 51) = Sum from i = 51 to 100 of (100 C i) * 2^100

Works out to what superprismatic came up with: 0.4602...

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it's 0.5 - 1/2 p(50).

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...the side with more ink by weight would be more likely to land downward?

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...the side with more ink by weight would be more likely to land downward?

I like that!

Any idea which side that is?

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Another real world question ...

When I read the question, I think of a tall building IN A CITY!

If this is the case [or even if it is a single tall building surrounded by country side - where there might be trees]. it is very likely that some portion of the bills will not land "on the ground" [in trees, window sills, fire escapes, tops of cars or trash cans, ...].

If we are simply looking at the pure probability of 100 coin tosses [or bill flutters], then i think the answer above is probably right, if we add a real world setting, the answer may be much lower.

It is probably just the lingering effects of too much sugar from Halloween.

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Chances are, most of the \$100 bills would end up in the hands of very excited people below and not on the ground. By the way, have you chosen a specific building for that important experiment in probability? When?

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There are 101 different possibilities from 0 to 100 up sides.

Of these, 50 are cases where there are more up sides (from 51 to100).

The probability then is 50/101 = 0.495
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yes,correct.. like 100 time toss of a coin (though it may stand on its side when curved)

for 2 times toss of a coin the chance is 25%
same: combin(2,1)/2^2= 0.50000
more : (1-.5)/2= 0.25000

for 4 times toss of a coin the chance is 31.25%
same: combin(4,2)/2^4= 0.37500
more: (1-.375)/2= 0.31250

for 100 times toss of a coin the chance is 46%
same: combin(100,50)/2^100= 0.07959
more: (1-.07959)/2= 0.46021

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