Question 321324
 tom likes to lie in bed in the morning. the probability that he is late for school is 0.1. 
What is the possibility that he is late on monday, tuesday & wednesday. 
Ans: 0.1^3
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What is possibility that he is late on monday & tuesday but on time on wednsday.
Ans: 0.1^2*0.9
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What is the possibility that he is late on only one of the three mornings?
Ans: P(x=1)= 3C1(0.1)^1(0.9)^2 = 3*0.1*0.81 = 0.2430
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Cheers,
Stan H.