which is a rational number but not an integer?

a.0
b.9/10
c.-18
d.2.529432

since (a) and (c) are both integers, that leaves (b) and (d).

Any decimal number you can write down represents a rational number, but it appears they want a fraction to be the answer, so I'd pick (b).

Just to clarify, Steve might be right about what they're looking for, but it's a bad question. d IS still a rational number.

To determine which option is a rational number but not an integer, we need to understand what rational numbers and integers are.

- Rational numbers: These are numbers that can be expressed as a fraction, where the numerator and denominator are both integers, and the denominator is not zero. In other words, rational numbers can be written in the form a/b, where a and b are integers.

- Integers: These are whole numbers (both positive and negative) and zero, without any fractional or decimal parts.

Now, let's examine each option:

a. 0: 0 is an integer since it is a whole number without any fractional or decimal parts. It can also be expressed as 0/1, where both 0 and 1 are integers. Therefore, 0 is both a rational number and an integer.

b. 9/10: This is a fraction where the numerator (9) and the denominator (10) are both integers. The denominator is not zero, so 9/10 is a rational number. However, it is not an integer because it has a fractional part. Therefore, option b, 9/10, is a rational number but not an integer.

c. -18: -18 is an integer since it is a whole number without any fractional or decimal parts. It can also be expressed as -18/1, where -18 and 1 are both integers. Therefore, -18 is both a rational number and an integer.

d. 2.529432: This number is a decimal with multiple decimal places. It is not a whole number and cannot be written as a fraction with integers as the numerator and denominator. Therefore, option d, 2.529432, is neither a rational number nor an integer.

In conclusion, the option that is a rational number but not an integer is option b, 9/10.