The probability of rolling an even prime number is 61
The numbers 2, 3, 5, 7 are prime, so the probability that a prime is selected is 4/10 = 40%. The probability that a prime is selected from 1 to 50 can be found in a similar way. The primes that are less than 50 are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43 and 47. There are 15 primes less than or equal to 50.