csvobo wrote:

The question is not "what percent of all the possible subcommittees include both Michael and Anthony?"

Then the answer would be 20%

The question is "what percent of all the possible subcommittees that include Michael also include Anthony?"

So you divide the number of possible combinations that include Michael and Anthony by the number of possible combinations that include Michael.

So, as zoinnk said there are 4 possible committees that include both Michael and Anthony.

I think it's easier to find the number of committees on which Michael does not appear at all, which would mean 5C3=10.

20-10 = 10 committees on which Michael appears.

4/10 = 40%

Even I did the same mistake as zoinnk ... Tricky words I guess ... zoinnk doesn't miss too many questions....

csvobo ... can you explain "to find the number of committees on which Michael does not appear at all, which would mean 5C3"

Thanks

_________________

"You have to find it. No one else can find it for you." - Bjorn Borg