Question

When the time by the watch is $20$ minutes past $7$, then the angle between the hands of the watch is :

• A. ${100}^o$
• B. ${90}^o$
• C. ${80}^o$
• D. ${95}^o$

Answer 1

The correct option is A ${100}^o$

$\theta =\frac{1}{2}(60H-11M)$

where,

$\theta$ is angle between the hour hand and minute hand

$H$ is the no. of hours

$M$ is in minutes

$\therefore \theta =\frac{1}{2}(60\times 7-11\times 20)$

$=$ $\frac{1}{2}\times 200$ $=$ ${100}^o$