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Logical Reasoning: Clock

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Practice Questions

Lane C — Arrangements & puzzles Study step 26 of 26 40 MCQs ready

Concept Explanation

Clock problems in placement LR (IndiaBIX / PrepInsta style) focus on the angle between hands, when hands coincide or are perpendicular, mirror time, and fast or slow watches. Use degree movement, not guesswork.

Hand movement

  • Minute hand: 360° in 60 min → 6° per minute.
  • Hour hand: 360° in 12 h → 0.5° per minute (30° per hour).
  • Relative speed: 5.5° per minute — hands close at this rate.

Angle at H:M (12-hour clock)

Angle = |30H − 5.5M| (take the smaller angle if the result exceeds 180°). Example: at 3:00, |90 − 0| = 90°.

Common patterns

Asked forApproach
Coincidence between H and H+1Minute ≈ 60H/11 after H o'clock
Right angle after H:00Solve |30H − 5.5M| = 90 for M
Mirror time(11 − H) : (60 − M) on a vertical mirror
Gain/loss per hourScale dial reading vs true time (ratio method)

How to solve fast

  1. Draw 12 at top; mark hour hand position as 30H + 0.5M degrees.
  2. Mark minute hand at 6M degrees.
  3. For overlap times, use relative speed 5.5°/min or the 60H/11 shortcut.