View Full Version : Probability
N4L
Dec 19, 2006, 04:42 PM
If You Flip A Coin And Toss A 1-6 Number Cube, What Is The Probability Of Choosing A Prime Number And Tails.
worthbeads
Dec 19, 2006, 05:36 PM
I believe it is 1/3 or 33.3%. You take the probability of getting tails, which would be 1/2 or 50%, and multiply that by 4/6 or 2/3 or 66%, the probability of getting a prime number. It would be 4 out of six because 1,2,3 and 5 are prime out of 1 2 3 4 5 and 6. So, 2/3*1/2=2/6 or 1/3.
Capuchin
Dec 19, 2006, 07:24 PM
Worthbeads' method is right but answer is wrong, 1 has not been considered to be prime for over 100 years now (at least in nearly all published papers). So in this case you get 1/2 x 1/2 = 1/4 or 25%
asterisk_man
Dec 20, 2006, 07:58 AM
I concur with Capuchin.
Of {1 2 3 4 5 6} {2 3 5} are prime
worthbeads
Dec 20, 2006, 08:53 PM
Yes I forgot about that 1 is not prime, but was it really necessary for you to take another blow to my profile, Capuchin?
Capuchin
Dec 20, 2006, 08:57 PM
Ooh sorry mate, I was just flagging up the incorrect information.
I'll give it back on your next thrilling post :)