Question

What fraction of a clockwise revolution does the hour hand of a clock turn through, when it goes from,

$\left(\mathrm{d}\right)12\mathrm{to}9$

Answer 1

Find the fraction of a clockwise revolution of the hour hand

As we know,

In watch, hour hand travel $12$ hours to complete one revolution.

When hour hand goes from $12\mathrm{to}9$. Then, hour hand travels total $9$ hours.

$$\begin{gathered} \because 12\mathrm{hours}=1\mathrm{Revolution} \\ \therefore 9\mathrm{hours}=\frac{1}{12}\times 9 \\ =\frac{3}{4}\mathrm{Revolution} \end{gathered}$$

Hence, when hour hand goes from $12\mathrm{to}9$. Then, it is equivalent to $\frac{3}{4}$ of a revolution, clockwise.