The HCF of $\frac{1}{2},\frac{3}{4},\frac{5}{6}$ and $\frac{7}{8}$ is :

$\frac{1}{24}$

HCF of fraction = \(\frac{HCF\;of\;numerator}{LCM\; of\;denominator}\)

The given fractions are :   $\frac{1}{2},\frac{3}{4},\frac{5}{6}$ and $\frac{7}{8}$.

LCM of 2, 4, 6, 8 = 24

HCF of 1, 3, 5, 7 = 1

The HCF of  $\frac{1}{2},\frac{3}{4},\frac{5}{6}$ and $\frac{7}{8}$  = \(\frac{1}{24}\)