Which decimal is terminating?

Correct answer: \(\frac{11}{50}\)

\(\frac{11}{50}=0.22\), so its decimal expansion terminates. A rational number \(\frac{p}{q}\) has a terminating decimal expansion only when, in lowest terms, the prime factors of \(q\) are only 2 and/or 5. Here, \(50=2\times5^2\). In contrast, \(24\), \(18\), and \(27\) contain 3 as a prime factor, so their decimal expansions are non-terminating recurring. Exam tip: First reduce the fraction, then check the prime factors of its denominator.