In a simultaneous throw of two coins, find the probability of getting

(i) two heads

(ii) exactly one head

(iii) no tail

(iv) at least one tail

(i) Outcomes = (H,H), (H,T),(T,H),(T,T)

Total number of outcomes = 4

Two heads occurs ony once so total number of favorable outcomes = 1

P(two heads)=

(ii) Outcomes = (H,H), (H,T),(T,H),(T,T)

Total number of outcomes = 4

Exactly one head occurs 2 times so a total number of favourable outcomes = 2.

P(exactly one head) = 2/4

(iii) Outcomes = (H,H), (H,T),(T,H),(T,T)

Total number of outcomes = 4

No tails occurs only one time when there are two heads = 1

so total number of favourable outcomes = 1

P(no tails) = 1/4

(iv) Outcomes = (H,H), (H,T),(T,H),(T,T)

Total number of outcomes = 4

Atleast one tails occurs 3 times

so total number of favourable outcomes = 3

P(atleast 1 tail) = 1/4