A clock is started at noon. By 10 minutes past 5, the hour hand has turned through
(a)145°
(b)150°
(c)155°
(d)160°
Answer
Answer (as printed): C
Explanation
Angle traced by the hour hand in 12 hrs = $360^{\circ}$. Angle traced by the hour hand in 5 hrs 10 min, i.e., $\frac{31}{6}$ hrs $=\left(\frac{360}{12} \times \frac{31}{6}\right)^{\circ}=155^{\circ}$.
Explanation as extracted from the printed page; notation may be imperfect.