jee-main 2020 Q70

jee-main · India · session1_07jan_shift1 Discrete Probability Distributions Expectation and Variance from Context-Based Random Variables

An unbiased coin is tossed 5 times. Suppose that a variable $X$ is assigned the value $k$ when $k$ consecutive heads are obtained for $k = 3, 4, 5$, otherwise $X$ takes the value $-1$. Then the expected value of $X$, is
(1) $\frac { 3 } { 16 }$
(2) $\frac { 1 } { 8 }$
(3) $- \frac { 3 } { 16 }$
(4) $- \frac { 1 } { 8 }$

An unbiased coin is tossed 5 times. Suppose that a variable $X$ is assigned the value $k$ when $k$ consecutive heads are obtained for $k = 3, 4, 5$, otherwise $X$ takes the value $-1$. Then the expected value of $X$, is\\
(1) $\frac { 3 } { 16 }$\\
(2) $\frac { 1 } { 8 }$\\
(3) $- \frac { 3 } { 16 }$\\
(4) $- \frac { 1 } { 8 }$

Paper Questions

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