multiple choice guessing probability (1 Viewer)

kuromusha · Oct 18, 2015

There are 240 questions, there are three choices in each question.

What is probability of guessing at least 168 questions correctly?

InteGrand · Oct 18, 2015

kuromusha said:
There are 240 questions, there are three choices in each question.

What is probability of guessing at least 168 questions correctly?

$Assuming you have a 1 in 3 chance of getting an answer right on a given guess, the answer is $\sum _{k=168}^{240}\binom{240}{k}\left(\frac{1}{3} \right)^k \left(\frac{2}{3} \right)^{240-k}$, which you should not be expected to have to calculate without use of a computer.$

InteGrand · Oct 19, 2015

Realised you probably just want a numerical answer lol.

According to http://www.wolframalpha.com/widgets/view.jsp?id=78baf4f3a070cc5b9b226664d2ce80ec and http://wolframalpha.com/input/?i=su...240+choose+k)(1/3)^(k)+*(2/3)^(240-k)&x=0&y=0 , the probability you're after is on the order of 10^(-31).

So basically '0'.

kuromusha · Jan 27, 2016

you're pretty good at LaTeX

leehuan · Jan 27, 2016

InteGrand is completely used to LaTeX. But there's no need to learn it when you can simply http://s1.daumcdn.net/editor/fp/service_nc/pencil/Pencil_chromestore.html

multiple choice guessing probability (1 Viewer)

kuromusha

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InteGrand

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InteGrand

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kuromusha

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leehuan

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