$100$ people are each given a lottery ticket and each of those tickets have the probability $p$ of winning a prize (independent of others)
To find the probability that exactly $10$ people win a prize, I have tried to find $P(X=10)$ using the binomial distribution formula. I know $X = 10$ and $n = 100$. But how can I know what $p$ is, when it isn't mentioned in the question?