Tickets 10, including 6 movie tickets, 10 people draw lots in turn. Solve the probability of the second person winning the movie ticket with the method of total probability.

A2={ The first person didn't get the movie ticket}

B={ The second person gets the movie ticket}

P(A 1)=6/ 10

P(A2)=4/ 10

P(B|A 1)=5/9

P(B|A2)=6/9

P(B)= P(a 1)P(B | a 1)+P(a 1)P(B | a 1)

=6/ 10 5/9+4/ 10 6/9

=54/90

=3/5