Xác suất

A fair die is rolled. What is the probability of rolling a number divisible by 3?

• 1/6

• 1/3

• 1/2

• 2/3

A fair die is rolled. What is the probability of rolling a number greater than 3?

• 1/6

• 1/3

• 1/2

• 2/3

A box contains 18 marbles of the same weight and size, in two colors: red and yellow. The number of yellow marbles is twice the number of red marbles. If one marble is randomly picked from the box, what is the probability of picking a yellow marble?

• 1/2

• 1/3

• 2/3

• 1/4

What is the probability of picking a yellow marble from a box containing 18 marbles, where the number of yellow marbles is double the number of red marbles?

• 1/3

• 1/2

• 2/3

• 3/4

A library shelf initially had 15 books, including some novels. After the librarian added 5 new novels, the probability of randomly picking a novel from the shelf became 0.75. How many novels were initially on the shelf?

• 5

• 10

• 12

• 15