Question 137564
There are eight people in an office. Each shows independently for a picture with probability 0.8. Let X denote the number that shows. This is a binomial problem. 
  probability that only one shows?: P(x=1)=8C1(0.8)(0.2)^7 = 0.00008192
  probability that everyone shows?: P(x=8)=8C8(0.8)^8(0.2)^0 = 0.1678
  probability that two or more show?P(2<=x<=8)= 1-[prob(x=0)+p(x=1)]= 0.9999
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Cheers,
Stan H.