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?

ok The number is greater than 2.

10 is divisible by 5 The number is not divisible by 5.

ok There are odd numbers but all numbers are less than 12 The number is even or less than 12.

Several are composite The number is neither prime nor composite.

sqrt (10) >3

The square root of the number is less than 3

So ...

The number is greater than 2.

The number is even OR less than 12.