40 students live in a dormitory. 5 have swine flu. If 4 students are selected at random, what is the probability that 1 or 2 of the 4 have swine flu?

Question

anonymous · Answer

(5/40)(4/39)((3/37)= 1.03950104*10^-3

anonymous · Answer

This is not the correct answer

anonymous · Answer

can u tell me what it is please,  i suck at probablity, my weakest subject

anonymous · Answer

anonymous · Answer

no problem.  so I found (40 nCr 4)= 91390 then  $$(35 nCr 3)(5 nCr 1)+(35 nCr 2)(5 nCr 2)=38675$$ then $$38675\div91390=0.423$$

anonymous · Answer

I actually posted that crsf29 and they didnt have the right answer either

anonymous · Answer

Did it work out for you? I could dig out my ProbStat book and help you, but it would take me about 20 minutes and I'd wake my roomies...Sorry.

anonymous · Answer

you dont have to do that I figured it out