which is a rational number but not an integer?

Question

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

Answer 1

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).

Answer 2

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.