Recent questions tagged gravner

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39
Roll a fair die repeatedly. Let X be the number of 6's in the first 10 rolls and let Y the number of rolls needed to obtain a 3.(d) Find an expression for $P(Y>10)$.
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40
Roll a fair die repeatedly. Let X be the number of 6's in the first 10 rolls and let Y the number of rolls needed to obtain a 3.(c) Find an expression $P$($X\geqslant 6$)...
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41
Roll a fair die repeatedly. Let X be the number of 6's in the first 10 rolls and let Y the number of rolls needed to obtain a 3.(b) Write down the probability mass functi...
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42
Roll a fair die repeatedly. Let X be the number of 6's in the first 10 rolls and let Y the number of rolls needed to obtain a 3.(a) Write down the probability mass functi...
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43
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45
Suppose that the probability that a person is killed by lighting in a year is, independently, $1/(500)$ million. Assume that the US population is $300$ million.
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47
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48
Let $X$ be a random variable with $P(X=1) =0.2,P(X=2)=0.3$, and $P(X=3)=0.5$. What is the expected value of $X$?
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49
Let $X$ be a random variable with $P(X=1) =0.2, P(X=2) = 0.3$, and $P(X=3) = 0.5$. What is the expected value of $X$?
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51
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52
Let $X$ be the number of Heads in $2$ fair coin tosses. Determine its p.m.f.
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55
Five married couples are seated at random around a round table.(b) Compute the probability that at most one wife does not sit next to her husband.
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56
Five married couples are seated at random around a round table.(a) Compute the probability that all couples sit together(i.e., every husband-wife pair occupies adjacent s...
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57
Ten fair dice are rolled. What is the probability that:(b) Each of the number $1,2,3$ appears exactly twice, while the number $4$ appears four times.
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58
Ten fair dice are rolled. What is the probability that:a) At least one $1$ appears.
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59
Ten fair dice are rolled. What is the probability that:(c) Each of the number $1,2,3$ appears at least once.