Which of the following is the smallest whole number?

1. 1

2. 0

3. -1

4. None of these

The additive inverse of -18 is

1. 18

2. -18

3. 0

4. $\dfrac{1}{18}$

Which of the following is a well-defined set?

1. The set of tall students in a class

2. The set of good books

3. The set of prime numbers less than 20

4. The set of beautiful flowers

Which of the following is an improper fraction?

1. $\dfrac{3}{4}$

2. $\dfrac{5}{8}$

3. $\dfrac{9}{7}$

4. $\dfrac{1}{3}$