0,1,2,3,4,5,6,7,8,9
The total outcome is 10 (each one is equally likely to happen.
The probability of getting any even number (2 OR 4 OR 6 OR 8 ) is 4, hence the P(getting an even number) =4/10 =2/5
Now the probability of getting the number 5 is (one favorable outcome):
P(5)= 1/10