Answer to Question #269972 in Electrical Engineering for Emyoung

Question

A die is tossed twice find the probability that;

a. A one and six occurs.

b. At least one three occurs.

c. Both numbers are the same.

Answer 1

Now, the probability of 2nd event is easy to calculate, it is the probability for getting the same number (whatever it might be 1,2,3,4,5 or 6) is 1/6.

The 1st and 3rd event should have same probability because of symmetry. Let that be x.

So, x + 1/6 + x = 1 (because these events are mutually exclusive and exhaustive)

Hence, x = 5/12