Total number of balls = 9
Therefore total number of possible outcomes = 9
Probability is the number of favourable outcomes divided by number of total 
possible outcomes.
a) Red and even number
No. of favourable outcomes = 
Number of balls that satisfy this condition = 2 (2 and 4)
Therefore probability = 2/9
b) Red OR Even number
No. of favourable outcomes = 
Number of balls that satisfy this condition = 6 (1,2,3,4,6,8)
Therefore probability = 6/9 = 2/3
c) White OR odd number
No. of favourable outcomes = 
Number of balls that satisfy this condition = 7 (1,3,5,6,7,8,9)
Therefore probability = 7/9
Hope you got it :)