On the planet Oz, there are 8 days in a week — Sunday to Saturday and another…

2025

On the planet Oz, there are 8 days in a week — Sunday to Saturday and another day called Oz Day. There are 36 hours in a day; each hour has 90 minutes, and each minute has 60 seconds. As on Earth, the hour hand completes two full rounds of the dial every day. Find the approximate angle between the hands of the clock on Oz at 14:40.

  1. A.

    83

  2. B.

    74

  3. C.

    129

  4. D.

    65

Show answer & explanation

Correct answer: C

Concept

On any clock, the angle between the hour and minute hands at a given moment equals the absolute difference between each hand's own angular position. Each hand's position is found as (its own degrees-per-minute rate) × (elapsed time), where the rate comes from how long that hand takes to complete one full 360° revolution of the dial — this holds regardless of how many hours are in a day or minutes in an hour.

Application

  1. Hour hand's rate: it completes the dial TWICE in Oz's 36-hour day, so one full revolution takes 36 ÷ 2 = 18 hours. Rate = 360° ÷ 18 = 20° per Oz-hour. Since 1 Oz-hour = 90 minutes, that is 20 ÷ 90 = 2/9° per minute.

  2. Minute hand's rate: it completes one full revolution every 90-minute Oz-hour. Rate = 360° ÷ 90 = 4° per minute.

  3. At 14:40 (14 hours 40 minutes), hour hand's position = 14 × 20° + 40 × (2/9)° = 280° + 8.89° ≈ 288.89°.

  4. Minute hand's position = 40 × 4° = 160°.

  5. Angle between the hands = |288.89° − 160°| = 128.89° ≈ 129° (already less than 180°, so this is the required angle).

Cross-check

Recompute from total elapsed minutes since 00:00: 14 × 90 + 40 = 1300 minutes. Hour hand position = 1300 × (2/9)° = 2600/9° ≈ 288.89° (matches). Minute hand position = (1300 mod 90) × 4° = 40 × 4° = 160° (matches) — confirming the angle is ≈129°.

Result

The angle between the hour and minute hands on Oz at 14:40 is approximately 129°.

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