Final answer:
All the given options, A. 10, B. 15, C. 7, D. -5, and E. 6.39, are rational numbers because they can all be expressed as fractions with integers in the numerator and a nonzero integer in the denominator.
Step-by-step explanation:
To determine which of the given numbers are rational numbers, we first need to understand what a rational number is. A rational number is a number that can be expressed as the quotient or fraction p/q of two integers, where the numerator p is any integer and the denominator q is any nonzero integer. Now, let's evaluate each option:
- A. 10 is a rational number because it can be expressed as 10/1 or any equivalent fraction.
- B. 15 is also a rational number for the same reason; it can be expressed as 15/1.
- C. 7 is a rational number, as it can be expressed as 7/1.
- D. -5 is a rational number because it is an integer and can be written as -5/1.
- E. 6.39 is a rational number. It is a terminating decimal and can be written as a fraction: 639/100.
All options A, B, C, D, and E represent rational numbers.