SOLUTION: a fair die is thrown twice Wat is the probability of a. a prime number from each throw

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Question 1069235: a fair die is thrown twice Wat is the probability of
a. a prime number from each throw

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
fair die has numbers from 1 to 6.
the prime numbers are 2, 3, 5.

a prime number can only be divided evenly by itself.
since all numbers can be divided evenly by 1, division by 1 doesn't count.

by definition, 1 is not a prime, even though it can only be divided by itself.

the prime numbers between 1 and 6 are therefore 2, 3, 5.

the non prime number between 1 and 6 are therefore 1, 4, 6.

there's a 50/50 chance you will roll a prime on each roll of the die.

so the probability that you will roll a prime on each roll of the die is .5.

the probability of rolling two prime number in a row would be .5 * .5 = .25

here's one definition from the web.

http://www.mathsisfun.com/definitions/prime-number.html