Math Is Fun Forum

anna_gg

Member

Registered: 2012-01-10

Posts: 232

Pick Random Numbers

Get two random numbers between 0 and 1. Subtract the smaller from the bigger. What is the probability that the result is <0.3? Is it greater than the probability to be > or equal to 0.3?
For what number (instead of 0.3) the probability for both cases is the same?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Pick Random Numbers

Hi;

Is it greater than the probability to be > or equal to 0.3?

I am not understanding you here, the P(≥.3) = .49

Did you check your post about the towns?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anna_gg

Member

Registered: 2012-01-10

Posts: 232

Re: Pick Random Numbers

Correct.
So, to have equal probability for both cases, we have to substitute 0.3 with 1-sqrt(0.50) = 1-0.707 = 0.292

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Pick Random Numbers

Hi;

Yes to get both equal to 1 / 2 we would need

Have you seen the answer given for,

http://www.mathisfunforum.com/viewtopic … 50#p279650

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.