Question

PLEASE HELP QUUUIIICKKKLLLYYYYYY. Tamara finds the sum of two number cubes rolled at the same time. The chart below shows all possible sums from the 36 possible combinations when rolling two number cubes. How many times should Tamara expect the sum of the two cubes be equal to 8 if she rolls the two number cubes 216 ​times?

Answer 1

From the chart, we can see that there are five possible ways to get a sum of 8:

- 2 + 6

- 3 + 5

- 4 + 4

- 5 + 3

- 6 + 2

Each of these outcomes can occur in 1 way, since there is only one way to roll a particular combination of two number cubes. Therefore, the probability of getting a sum of 8 is:

P(sum of 8) = 5/36

If Tamara rolls the two number cubes 216 times, we can expect her to get a sum of 8 about:

Expected number of sums of 8 = (number of rolls) x P(sum of 8)

Expected number of sums of 8 = 216 x 5/36

Expected number of sums of 8 = 30

Therefore, Tamara should expect to get a sum of 8 about 30 times if she rolls the two number cubes 216 times.