Can some one explain how to solve this? PLZ HELP!!

Question

anonymous · Answer

attachment

anonymous · Answer

@joyce153  hello

anonymous · Answer

hi I can u help with this problem?

anonymous · Answer

Is there somebody to help? Or Shall I?

anonymous · Answer

lol well no one has helped yet so PLZ do

anonymous · Answer

a. P(atleast one has not operated...) = 1 - P(all the three had operated under the influence...)
                                                     = 1 - (30C3)/(100C3)
I assumed that there are 100people in that age group. So, 30% of 100 is 30 which is the number of people who had operated under the influence of sugar

anonymous · Answer

Did u know this formula?$$P(x..k)=\left(\begin{matrix}x \ k\end{matrix}\right)P_{s}^{k}P_{f}^{x-k} $$

anonymous · Answer

b. It is the same but replace 30 by 70

anonymous · Answer

I think that formula works very well..

anonymous · Answer

It is the correct way.

anonymous · Answer

Can I post how we will solve it?

anonymous · Answer

Why don't you explain it for her? May be she can understand it better if explained. @Zekarias

anonymous · Answer

What??? How can probability be greater than 1?? @Zekarias