Which statement is true about the relationships between the number sets?

1. Whole numbers include all natural numbers and 0
2. Some irrational numbers are also integers
3. All rational numbers are also integers
4. Not all natural numbers are real numbers

The statement that is true about the relationships between the number sets is:

4. Not all natural numbers are real numbers.

The statement that is true about -9 is:

1. It is both an integer and a whole number.

To convert the mixed number $3.39 9/10 to a decimal, we can add the whole number part (3) to the decimal part (0.39) plus the fraction (9/10).

Using the fraction, we divide 9 by 10 to get 0.9.

Adding 0.39 and 0.9 gives us 1.29.

Therefore, a gallon of gas costs $3.29 as a decimal.

Which of the following is true about -9 ?

1. It is both an integer and a whole number
2. It is an integer but not a rational number
3. It is a whole number but not an integer
4. It is an integer but not a whole number

A sign in a gas station advertises gas at the rate of $3.39 9/10 per gallon. How many dollars does a gallon cost, writing the price strictly as a decimal?

Which set of number is always rational?

1. Integers
2. Positive numbers
3. Fractions
4. Decimals

The set of numbers that is always rational is:

3. Fractions.

A fraction can always be expressed as the ratio of two integers, making it a rational number.