When a fair coin is tossed 4 times then the sample space is
S = {HHHH, HHHT, HHTH, HTHH, THHH, HHTT, HTHT, HTTH, THHT, THTH, TTHH, HTTT, THTT, TTHT, TTTH, TTTT}
∴...
If a coin is tossed three times, then the sample S is
`S={HHH,HHT, HTH, HT T ,THH,THT, T TH, T T T }`
`thereforen(S)=8.`
(i) `A={HHH, HTH, THH, T TH]`...
`P(E_(1))=1-["P(all heads)+P(all tails")]`
`=1-[(1)/(2^(n))+(1)/(2^(n))]=1-(1)/(2^(n-1))`
`P(E_(2))=P("no head)+P(exactly one head")`
`=(1)/(2^(n))+^(""n)C_(1).(1)/(2^(n))=(n)/(2^(n))`
`P(E_(1)nnE_(2))=("exactly one head and"(n-1)till)`
`=^(""n)C_(1).(1)/(2).(1)/(2^(n-1))=(n)/(2^(n))`
If `E_(1)and E_(2)` are indipendent, then
`P(E_(1)nnE_(2))=P(E_(1)).P(E_(2))`
`implies(n)/(2^(n))=(1-(1)/(2^(n-1)))((n+1)/(2^(n)))`
`impliesn=(1-(1)/(2^(n-1)))(n+1)`
Correct Answer - C
The required probability is
1- probability of getting equal number of heads and tails
`=1-""^(2n)C_(n)((1)/(2))^(n)((1)/(2))^(2n-n)`
`=1-((2n)!)/((n!)^(2))xx(1)/(4^(n))`
Correct Answer - B
Let the probability of getting a tail in a single trial be `p=1//2.` The number of trials be n=100 and the number of trials in 100 trials...
Correct Answer - C
`(c )` The cases for `a_(1){H,T}` i.e, `a_(1)=2`
The cases for `a_(2){HT,TH,TT}`, `a_(2)=3`
For `n ge 3` , if the first outcome is `H`, then next just...