Answer
Event A= 1/2
Event B= 1/4
Procedure
To get the probability of completely independent events you will need to divide the possibilities of getting a particular number over the total number of possibilities
Event A: 2/4 or 1/2 (The odd numbers are 1 and 3)
Event B: 1/4 (There is only one 4 in the range among 1 to 4)