10 people will get tickets, and the allocation will be decided by drawing lots. (1) Knowing that the first four people have never touched it, find the probability that the fifth person has touched it. Solution process
The first time was110, the second time was 1/9, and the third time was 1/8,,,
The first four times were not 9/ 10, 8/9,,,
The fifth touch is 1/6.
So the answer is
9/ 10x 8/9x 7/8x 6/7x 1/6 = 1/ 10