Concept:The density property of rational numbers states that between any two distinct rational numbers, there are infinitely many rational numbers. Also, every non-zero rational number has a multiplicative inverse (reciprocal).
Explanation:Option A is true because rational numbers are dense – between any two, there are infinitely many others.
Option B is true because 0 (a whole number) always lies between a positive and a negative rational number.
Option C is true because for any non-zero rational
ba​, its multiplicative inverse is
ab​.
Option D is false: There cannot be a pair with only one rational between them because between any two rationals, infinitely many rationals exist.
Answer:D