Question

a die is rolled in such a way that even faces are twice as likely to occur as the odd faces. what is the probability that a prime number shows up when rolled?

Answer 1

since odds come up 1/3 of the time, I guess it depends on how many of the odd faces are primes. You haven't said how many faces are on the die.

Answer 2

anyway, since 2/3 of the odd numbers on a regular die are primes, that means that a prime will come up 2/9 of the time.

Answer 3

well they have to add up to one and there are 6 sides
p(1) = n prime
p(2) = 2n prime
p(3) = n prime
p(4) = 2n
p(5) = n prime
p(6) = 2n

sum of p s is one
9 n = 1
n = 1/9
primes are 5n or 5/9