A coin is tossed three times. Find P (A/B) in each of the following:
A=At least two heads, B=At most two heads
When a coin is tossed three times, we have following outcomes
{HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}
Total outcomes =8
A= at least two heads ={HHH, HHT, THH, HTH} = 4
Therefore probability of occurrence of event A = P(A) =
B= at most two heads ={HHT, HTH, HHT, THT, TTH, TTT, HTT} =7
Therefore probability of occurrence of event B = P(B) =
Now Also we want P (A ∩ B) = probability of occurrence of both events A and B
= occurrence of atleast and atmost two heads ={HHT, HTH, THH} =3
Hence, probability of occurrence of both events A and B = P (A ∩ B)=
Therefore, =
= (answer)