Answer:
The required probability is 
Step-by-step explanation:
Let us take the events,
A = The sum of the two numbers is less than 5
B = The first number is odd and is less than 5.
Now, each of the two numbers can take value from 1 to 9.
So, the total number of outcomes = 9 × 9 = 81.
Also, the first number is odd and less than 5.
Then, the possibility for the first number = 1 and 3
While the possibility for the second number = 1 to 9
So, P(B) = 
Now, we see that,
= The event having sum of the two numbers less than 5 with first number odd and less than 5.
The possible numbers are, (1,1), (1,2), (1,3) and (3,1).
So,
= 
Hence,

i.e. 
i.e. 
i.e. 
i.e. P(A|B) = 
Thus, the required probability is
.