Wikipedia:Reference desk/Archives/Mathematics/2013 May 5

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May 5

Rolling all 6 numbers

How do I go about working out how many times I need to roll a die before I can expect to have rolled all six numbers? (And I don't know what I mean by "expect" here...) -- SGBailey (talk) 07:42, 5 May 2013 (UTC)

This is a special case of the coupon collector's problem. HTH, Robinh (talk) 08:35, 5 May 2013 (UTC)

With expectation (arithmetic mean of all number of times required, given a large number of repeats) 14.7 for all six faces to appear.←86.128.43.105 (talk) 11:40, 5 May 2013 (UTC)

Thank you both (Rh & 86). Just what I needed. -- SGBailey (talk) 17:35, 5 May 2013 (UTC)