Question

Select the correct answer. A number is selected at random from the set {2, 3, 4, ... 10}. Which event, by definition, covers the entire sample space of this experiment? A. The number is greater than 2. B. The number is not divisible by 5. C. The number is even or less than 12. D. The number is neither prime nor composite. E. The square root of the number is less than 3.

Answer 1

c

Explanation:

Answer 2

C. The number is even or less than 12.

Explanation:

Let's analyze each event:

A. The number is greater than 2.

This doesn't cover the case when we get number 2. Because 2 is equal to 2, not greater.

B. The number is not divisible by 5.

10 and 5 are divisible by 5, so this doesn't cover the entire sample space.

C. The number is even or less than 12.

Let's notice that every number from {2, 3, 4, ... 10} is less than 12, so the even part of the event doesn't play any role. This covers the entire sample space.

D. The number is neither prime nor composite.

The definition of prime number is exactly the opposite of composite number, so there can't be a number that's neither both. This event doesn't cover any number of the set.

E. The square root of the number is less than 3.

This doesn't cover number 10, because the square root of 10 is approx. 3,16 that's greater than 3.