Question

An accurate clock shows 8 O'clock in the morning. Through how many degrees will the hour hand rotate when the clock shows 20:00 (8 O'clock in the evening)?

• A. 144°
• B. 150°
• C. 168°
• D. 180°

Hint:

To find the angle turned by the hour hand, simply multiply the number of hours by 30°, as the hour hand moves 30° per hour.

Answer 1

The Correct Option is D

Step 1: The hour hand on a clock completes a full rotation (360°) in 12 hours. Thus, the angle turned by the hour hand in 1 hour is: \[ \frac{360^\circ}{12} = 30^\circ. \] Step 2: From 8:00 AM to 8:00 PM, the total time is 12 hours. 
Step 3: Therefore, the hour hand will rotate by: \[ 12 \times 30^\circ = 360^\circ. \] But from 8:00 AM to 8:00 PM, the hour hand rotates half of the circle, which is 180°. Thus, the answer is \( \boxed{180^\circ} \).