Question

. A coin is tossed three times. find the probability of getting
(i)at least one head (ii) at most one head​

Answer 1

Step-by-step explanation:

Sample space: {

HHH,HTH,THH,TTH

HHT,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)

=

8

3

+

8

1

(using formula=P(event)=

Total no. of possible outcomes

No. of favourable outcomes

P(A)=

8

4

=

2

1

∴P(A)=

2

1

(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)

=

8

1

+

8

3

=

8

4

=

2

1

P(C)=

2

1

.