Confused by quadratic distribution and hypergeometric distribution ~ ~ For example, two out of ten are good, and they are distributed according to hypergeometric distribution, for example, the first p

Confused by quadratic distribution and hypergeometric distribution ~ ~ For example, two out of ten are good, and they are distributed according to hypergeometric distribution, for example, the first person draws. This is your own analysis error.

For example, the probability that the first person draws a good card is 2/ 10= 1/5.

So what is the probability that the second person will get a good draw? It is analyzed in two situations.

1, the first person wins the lottery, so the probability of the second person winning the lottery is1/9 *1/5 =1/45.

2. If the first person doesn't draw a good card, the probability that the second person draws a good card is (1-1/5) * 2/9 = 4/5 * 2/9 = 8/45.

So the probability that the second person draws a good card is1/45+8/45 = 9/45 =1/5.

It is equal to the probability that the first person draws a good ticket. Is fair.

Where are you wrong? You only consider the case of 1. The probability that the first person gets a good ticket and the second person gets a good ticket is1/9 *1/5 =1/45.

Do not consider 2. If the first person doesn't win the lottery, the probability of the second person winning the lottery is (1-1/5) * 2/9 = 4/5 * 2/9 = 8/45.