Rational numbers include which of the following?

• A. Include all integers, decimals, and fractions.
• B. Include only integers.
• C. Include only irrational numbers.
• D. Include only terminating decimals.

Answer: (A)

Rational numbers are numbers that can be written as a ratio of two integers, a/b, with b not zero. That means every integer is rational (like 5 = 5/1), and every fraction is rational. Decimals that terminate (like 0.75) or repeat (like 0.333...) also represent fractions, so they are rational as well. Because of this, rational numbers include all integers, decimals, and fractions. The other statements limit rational numbers in ways that aren’t true: some decimals don’t terminate but repeat and still are rational; some numbers are irrational and cannot be written as a ratio of integers; and not all terminating decimals cover all rational numbers.