(i) $-\frac{1}{4}$ is a negative number and 0 is neither positive nor negative.
Since every negative number is less than 0,
Hence, $-\frac{1}{4} \lt 0$
(ii) $\frac{1}{4}$ is a positive number and 0 is neither positive nor negative.
Since 0 is less than every positive number,
Hence, $\frac{1}{4} \gt 0$
(iii) $-\frac{3}{8}$ is a negative number and $\frac{2}{5}$ is a positive number.
Since every negative number is less than every positive number,
Hence, $-\frac{3}{8} \lt \frac{2}{5}$
(iv) $\frac{7}{-12} = \frac{-7}{12}$
By Division Method,
$$\begin{array}{l|r} 2 & 8, 12 \\ \hline 2 & 4, 6 \\ \hline 2 & 2, 3 \\ \hline 3 & 1, 3 \\ \hline & 1, 1 \end{array}$$
LCM of 8 and 12 = 2 × 2 × 2 × 3 = 24
$\frac{-5 \times 3}{8 \times 3} = \frac{-15}{24} \text{ and } \frac{-7 \times 2}{12 \times 2} = \frac{-14}{24}$
Since -15 < -14,
Hence, $\frac{-5}{8} \lt \frac{7}{-12}$
(v) $\frac{5}{-9} = \frac{-5}{9} \text{ and } \frac{-5}{-9} = \frac{5}{9}$
$\frac{-5}{9}$ is negative and $\frac{5}{9}$ is positive.
Since every negative number is less than every positive number,
Hence, $\frac{5}{-9} \lt \frac{-5}{-9}$
(vi) $\frac{5}{-6} = \frac{-5}{6}$
By prime factorization,
$$\begin{array}{l|r} 2 & 8 \\ \hline 2 & 4 \\ \hline 2 & 2 \\ \hline & 1 \end{array} \quad \text{ and } \quad \begin{array}{l|r} 2 & 6 \\ \hline 3 & 3 \\ \hline & 1 \end{array}$$
LCM of 8 and 6 is 2 × 2 × 2 × 3 = 24
$\frac{-7 \times 3}{8 \times 3} = \frac{-21}{24} \text{ and } \frac{-5 \times 4}{6 \times 4} = \frac{-20}{24}$
Since -21 < -20,
Hence, $\frac{-7}{8} \lt \frac{5}{-6}$
(vii) $\frac{-3}{-8} = \frac{3}{8}$
On cross-multiplying $\frac{2}{7} \text{ and } \frac{3}{8}$:
$2 \times 8 = 16 \text{ and } 7 \times 3 = 21$
Since 16 < 21,
Hence, $\frac{2}{7} \lt \frac{-3}{-8}$