If you draw lots for three times, you will get the natural number n n, and the value range of n is 1 1 to 666, including11and 666. What's the difference between drawing lots three times?

I haven't encountered the problem of probability for a long time. Let me talk about it. The number of natural numbers that can be drawn is 666-11+1= 556.

For the first time, whatever you smoke is a number, which has nothing to do with the problem.

The number drawn for the second time is different from that for the first time, that is, the number that can be drawn is 556- 1.

Similarly, 556-2 people can be drawn for the third time.

The probability of three different times is equal to 1x(555/556)x(554/556).

Some people may think that 554/556 is right, and it is necessary to consider whether the number and probability of the second lottery are the same.