PROBABILITY EXERCISE

Probability Exercise :

1. What is the probability of getting a sum 9 from two throws of a dice?

Explanation :

                               In two throw of a dice , n (S) = (6x6)=36

                        Let E = event of getting a sum= {(3,6),(4,5),(5,4),(6,3)

                                   P(E) = n(e)/n(s) = 4/36 = 1/9

2. Two dice are rolled once. Calculate the probability that the sum of the numbers on the  two dice is 5
Possible outcomes (Sample Space) = {(1, 1), (1, 2),...............,(1, 6), (2, 1), (2, 2),................,(2, 6), (3, 1), (3, 2),...........,(3, 6), .............,(4, 1), (4, 2),..........,(4, 6), (5, 1), (5,2),...............,(5, 6), (6, 1), (6, 2),......................,(6, 6)}

Total possible outcomes = 36

Number of outcomes of the experiment that are favorable to the event that a sum of two events is 6

=> Favorable outcomes are: (1, 5), (2, 4), (3, 3), (4, 2) and (5, 1)

Number of favorable outcomes = 5.

Use, probability formula = Number offavorable outcomes / Total number of possible outcomes

= 536536

The probability of a sum of 6 is 536536.