When a die is thrown, there are total six outcomes, i.e., 1, 2, 3, 4, 5 and 6.

(i) (a) 2, 3, 5 are prime numbers. So there are 3 outcomes out of 6. Therefore, probability of getting a prime number = 3/6 = 1/2

(b) 1, 4, 6 are not the prime numbers. So there are 3 outcomes out of 6. Therefore, probability of getting a prime number = 3/6 = 1/2

(ii) (a) Only 6 is greater than 5. So there is one outcome out of 6. Therefore, probability of getting a number greater than 5 = 1/6

(b) Numbers not greater than 5 are 1, 2, 3, 4 and 5. So there are 5 outcomes out of 6. Therefore, probability of not getting a number greater than 5 = 5/6