1.

 Three coins are tossed. What is the probability of getting (i) all heads, (ii) two heads, (iii) at least one head, (iv) at least two heads?

Answer»

Let ‘S’ be the sample – space. Then S = { HHH, HHT, HTH, THH, HTT, THT, TTH, TTT } 

(i) Let ‘E1’ = Event of getting all heads, Then E1 = { HHH } 

 |E1| = 1 

 P(E1) = |E1| / |S| = 1 / 8 

(ii) Let E2 = Event of getting ‘2’ heads. Then: 

 E2 = { HHT, HTH, THH } 

 |E2| = 3 P (E2) = 3 / 8 

(iii) Let E3 = Event of getting at least one head. Then: 

 E3 = { HHH, HHT, HTH, THH, HTT, THT, TTH } 

 |E3| = 7 

 P (E3) = 7 / 8 

(iv) Let E4 = Event of getting at least one head, Then: 

 E4 = { HHH, HHT, HTH, THH, } 

 |E4| = 4 P 

(E4) = 4/8 = 1/2


Discussion

No Comment Found

Related InterviewSolutions