Answer:
The required probability (P) is :

Explanation:
Probability of meeting random person who has same birthday as you =

Probability of meeting random person who do not has same birthday as you =

Now, to find the required probability that the 25th person you meet is the first person who has the same birthday as you = (Probability that the first 24 persons we meet did not have same birthday as you) × (Probability that the first 25 persons we meet has same birthday as you)
Therefore,
