Probability

Question

You want to know the probability that you will roll doubles or a sum of six with two dice. Calculate the probability. 

 

If you toss four coins, what is the probability that you will get exactly 1 or 4 heads? Calculate the Probability. 

Answer 1

When rolling two dice, there are 36 possible outcomes.  There are 6 sets of doubles and a sum of six can be (1,5), (2,4), (3,3), (4,2) and (5,1).  but we cant double count the (3,3).  So there are a total of 10 combinations of 6 or doubles.

 

Therefor the probability is 10/36 = 5/18