Aptitude Day 131

Problems on Probability: 

    

1. In a simultaneous throw of 2 coins, the probability of getting at least 1 tail is:

Solution:

                 S = {TT, TH, HT, HH}

                 E = {TH, HT, TT}  

         

                 P(E) = n(E)/ n(S)

                        = 3/4.

2. 3 unbiased coins are tossed. What’s the probability of getting at least 2 tails?

Solution:

                S = {TTT, TTH, THT, HTT, HHH, HHT, HTH, THH}

                 E = {TTT, TTH, THT, HTT}  

         

                 P(E) = n(E)/ n(S)

                        = 4/8

                        = 1/2.