Question

A six-sided number cube is to be rolled 30 times. How many times do you expect to roll on an even number?

Answer 1

There are three even numbers on a six-sided number cube: 2, 4, and 6. Therefore, the probability of rolling an even number on any given roll is 3/6 or 1/2.

If we roll the cube 30 times, we can expect to roll an even number approximately 15 times, based on probability.

Expected number of even rolls = probability of rolling an even number x number of rolls
Expected number of even rolls = (1/2) x 30 = 15

Answer 2

prob(even) = 1/2

so out of 30 tries , we would expect to get 15 evens

Answer 3

Yes, that is correct.

Answer 4

A survey was conducted with 150 respondents that asked about their favorite activities during winter. There were 30 people who favored building a snowman, 80 people who liked skiing, and 40 who preferred sledding. What is the experimental probability that someone’s favorite activity is sledding? Write your answer in the simplest form of fraction.