Aptitude Day 135

Problems on Probability:

1. In s simultaneous throw of 2 dice, what’s the probability of getting 2 numbers whose product is odd?

Solution:

                n(S) = 36

                 E = {(1,1), (1,3), (1,5), (3,1), (3,3), (3,5), (5,1), (5,3), (5,5)}

                 P(E) = n(E)/ n(S)

                         = 9/36

                         = 1/4.

2. Tickets numbered 1 to 30 are mixed up and then a ticket is drawn at random. What’s the probability that the ticket drawn bears a number which is a multiple of 4?

Solution:

                n(S) = 30

                 E = {4, 8, 12, 16, 24, 28}

                 P(E) = n(E)/ n(S)

                         = 7/36.