The angle between the minute hand and the hour hand of a clock when the time is 8.30, is · ABC26GN5180
Subject: General Aptitude · Chapter: Clocks · Exam: R.R.B. 2006
The angle between the minute hand and the hour hand of a clock when the time is 8.30, is
(a)80°
(b)75°
(c)60°
(d)105°
Answer
Answer (as printed): B
Explanation
Angle traced by hour hand in $$\frac{17}{2} \mathrm{hrs}=\left(\frac{360}{12} \times \frac{17}{2}\right)^{\circ}=255^{\circ} .$$ Angle traced by min. hand in 30 min. $=\left(\frac{360}{60} \times 30\right)^{\circ}=180^{\circ}$. $$\text { ∴ Required angle }=(255-180)^{\circ}=75^{\circ} .$$
Explanation as extracted from the printed page; notation may be imperfect.