Question

Which of the following is a terminating decimal number?

• A. $-\frac{11}{325}$
• B. $\frac{5}{99}$
• C. $\frac{7}{625}$
• D. $-\frac{9}{143}$

Answer 1

The correct option is C $\frac{7}{625}$

$\frac{7}{625}=\frac{7}{5^4}$
$\because$ denominator has only $5$ as a prime factor.
$\therefore$ it results in terminating decimal.

$-\frac{11}{325}=-\frac{11}{5^2\times 13}$
$-\frac{9}{143}=-\frac{9}{11\times 13}$
$\frac{5}{99}=\frac{5}{3^2\times 11}$
All the above three options does not have $2$ and $5$ as their only prime factor, hence they results in non-terminating decimal.