Three coins are tossed once. Find the probability of getting: all heads (ii) at least two heads (iii) at most two heads (iv)  no heads    (v) exactly one tail    (vi) exactly 2 tails (vii) a head on first coin.

Explanation

`S{HHH,HHT,HTH,HT T,THH,THT,T TH,T T T}`

`A[HHH}`

`B{HHH,HHT,THH,HTH}`

`C{HHH,HHT,HTH,HT T,THH,THT,T TH}`

`D{TTT}`

`P(A)=1/8`

`P(B)=1/2`

`P(C)=7/8`

...