Math Is Fun Forum

nevinsmith

Member

Registered: 2010-05-19

Posts: 39

statistics summation question

hi guys me again!

Q- Jack and Morgan are gambling, on a roulette wheel there are 10 blacks and 30 reds, they both take turns at spinning the wheel, the first person to land their dice on black wins.
If jack goes first, what is his probability of winning?

so i figured out this is a summation question to infinity

b=1/4    r=3/4

the probability would be
b+brr+brrrr+brrrrr.....

so b+ b(sum of n=0 n=inf)(r^2)^n
where r<1

now how do i solve this?

sorry i don't know how to write the summation notation on here!
now how do i solve this?

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: statistics summation question

Hi nevinsmith,

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"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: statistics summation question

For the notations,

check this: http://www.mathisfunforum.com/viewtopic.php?id=4397
and : http://www.codecogs.com/latex/eqneditor.php

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"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."