Question

A coin is tossed three times ,then find the probability of getting head on middle

Answer 1

Answer:

So the probability of getting one head is the probability of getting one of those 3 outcomes, i.e. 3/8. There are 2x2x2=8 possible outcomes of which 3 meet the requirement: HTT, THT and TTH. These are all equally likely, with probability 1/8.

Answer 2

Answer:

Sample space: {HHH,HTH,THH,TTHHHT,HTT,THT,TTT}

Total number of possible outcomes=8

(1) A getting at least two heads

P(A)=P(getting two heads)+P(getting 3 heads)

=83+81

(using formula=P(event)=Total no. of possible outcomesNo. of favourable outcomes

P(A)=84=21

∴P(A)=21

(2) B: getting exactly two heads

P(B)=3/8

(3) C: getting almost one head

P(C)=P(getting no head)+P(getting 1 head)

=81+83=84=21

P(C)=21.