Anyone would like to show me how to solve these problems? Thanks a lot.

redpot

1. A的发生概率为0.6，B发生的概率为0.5，问A,B都不发生的最大概率？


2. There are 6 groups in a room. Each group consists of 3 men. How many handshakes will there be if each man only shakes hands with people who are outside his group?

redpot

As to 1, i am still a little bit confused.  Does it mean that 0.5 possibility for both A and B occur at the same time?  How about A with 0.6, B with 0.7, C with 0.8, then the possibility for all of them not occur?  Is it 0.2?  
Well, to 2, thank you very much.  I got it.  I can also get it by (C6,2)*(3*3).

redpot

Multiple?  0.4*0.5=0.2?  or 0.2*0.3*0.4=0.024?

redpot

So how about A with 0.6, B with 0.7, C with 0.8, then the possibility for all of them not occur?  If they are dependent, the answer is 0.2.  What if they are independent?

redpot

Thanks so much.