What is the angle in degree between the hour hand and the minute hand

What is the angle in degree between the hour hand and the minute hand of a clock when the time it shows is 5:20 PM?

35°
40°
42°
45°
This question was previously asked in
UPSC CBI DSP LDCE – 2023
At 5:20 PM, the time is 5 hours and 20 minutes.
First, calculate the angle of the hour hand from the 12 o’clock position.
The hour hand moves 360° in 12 hours, or 30° per hour (360°/12).
It also moves due to the minutes past the hour. In 60 minutes, the hour hand moves 30°. So, in 1 minute, it moves $30°/60 = 0.5°$.
At 5:20, the time is 5 hours and 20 minutes past 12. The total time in minutes past 12 is $(5 \times 60) + 20 = 300 + 20 = 320$ minutes.
Angle covered by hour hand = $320 \times 0.5° = 160°$.
Alternatively, angle = (5 hours $\times$ 30°/hour) + (20 minutes $\times$ 0.5°/minute) = 150° + 10° = 160°.

Second, calculate the angle of the minute hand from the 12 o’clock position.
The minute hand moves 360° in 60 minutes, or 6° per minute (360°/60).
At 20 minutes past the hour, the minute hand is at the 20 minute mark.
Angle covered by minute hand = $20 \times 6° = 120°$.

The angle between the hour hand and the minute hand is the absolute difference between their positions.
Angle = $|160° – 120°| = 40°$.

The hour hand moves 0.5° per minute. The minute hand moves 6° per minute. The angle between the hands at H hours and M minutes past 12 is $|30H – 5.5M|$ degrees (where $5.5M = (6M – 0.5M)$, the difference in speeds). Using the position method: Hour hand angle = $30H + 0.5M$. Minute hand angle = $6M$. Angle = $|(30H + 0.5M) – 6M| = |30H – 5.5M|$. At 5:20, H=5, M=20. Angle = $|30 \times 5 – 5.5 \times 20| = |150 – 110| = 40°$.
Clock problems require understanding the relative speeds of the hour and minute hands. The 12-hour mark is usually taken as the reference point (0 degrees). Angles are measured clockwise from 12.
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