Which of the following fractions is greater than 34 and less than 56 ?

Answer: Option C

$$\begin{array}{rl}& \frac{3}{4}=0.75,\\ & \frac{5}{6}=0.833,\\ & \frac{1}{2}=0.5,\\ & \frac{2}{3}=0.66,\\ & \frac{4}{5}=0.8,\\ & \frac{9}{10}=0.9\end{array}$$
Clearly, 0.8 lies between 0.75 and 0.833
$$\therefore \frac{4}{5}\text{lies between}\frac{3}{4}\text{and}\frac{5}{6}$$