Question

Suppose you roll two six-sided dice, one red and one blue. Each is labeled 1 through 6. What is the probability that you roll a two on the blue dye and the sum of both dice is greater than 4

Answer 1

Answer: 1/9

Work Shown:

If the blue die shows a "2", then the red die must take on the values from the set {3, 4, 5, 6} in order for the sum of both dice to be larger than 4.

2+3 = 5

2+4 = 6

2+5 = 7

2+6 = 8

There are 6*6 = 36 total ways to roll two dice and exactly 4 ways to get the conditions stated above. The probability of getting a sum greater than 4 is 4/36 = 1/9.