Which of the following numbers is a factor of every number?

1. 0

2. 1

3. 2

4. 3

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

What is the place value of 7 in the number 45.672?

1. 7 tenths

2. 7 hundredths

3. 7 ones

4. 7 thousandths

The ratio of 3 km to 750 m is

1. 1:250

2. 4:1

3. 1:4

4. 250:1