Dice Question

Question

An ordinary (fair) die is a cube with the numbers 1 through 6 on the sides (represented by painted spots). Imagine that such a die is rolled twice in succession and that the face values of the two rolls are added together. This sum is recorded as the outcome of a single trial of a random experiment. Compute the probability of each of the following events:

Event A: The sum is greater than 9.
Event B: The sum is an even number.

Write your answers as exact fractions.

Answer 1

Hi Thomas, when rolling a single die two times, there are 36 possible sums for what appears on the die.

 

Out of the 36 possible sums, only six are greater than 9.

 

P(sum > 9) = 6 / 36, or 1 / 6

 

Of the 36 possible sums, 18 are even and 18 are odd.

 

P(of an even number) = 18 / 36, or 1 / 2.

 

Questions?