perplexus.info :: Probability : N dice

N dice (Posted on 2017-05-25)

In "5 dice" Andy had five regular dice. Now he has a total of N regular dice. He claims that the odds of rolling exactly M sixes is exactly half as likely as rolling (M-1) sixes. (M < N).

For what values of N is this true?

State the pattern if there is one.

Express M as a function of N.

Submitted by Larry

Rating: 3.5000 (2 votes)

Solution: (Hide)

N can be 6,13,20, ... or 7i-1 where i=1,2,3 etc
M = (2/7)(N+1)

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
computer aided solution	Charlie	2017-05-25 12:14:14
re: Solution	Steve Herman	2017-05-25 12:12:41
Solution	hoodat	2017-05-25 11:42:49

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