Angle at 7:20 — Mathematical Reasoning Aptitude Question
Angle at 7:20: What is the angle between the hands of a clock at 7:20? Answer and worked solution on CodeKairo.
- Topic: Mathematical Reasoning
- Section: Logical Reasoning
- Difficulty: Medium
- Time target: 60 seconds
Question
What is the angle between the hands of a clock at 7:20?
Options
- 90°
- 100°
- 110°
- 120°
Show the answer and the worked solution
Correct answer: B. 100°
Worked solution
- Angle = |30 × 7 − 5.5 × 20| = |210 − 110| = 100°.
Answer: 100°.
The idea
Remember that the hour hand drifts 0.5° per minute, which is exactly what the 5.5 in the formula accounts for.
Shortcut. The minute hand sits on the 4; from the 4 to the 7 is three hour-marks (90°), plus the hour hand's 20-minute drift of 10° beyond the 7, so 100°.
Common trap. "90°" — counting the three hour-marks from 4 to 7 and treating the hour hand as parked on the 7, ignoring the 10° it has moved by 7:20.