A clock loses 5 minutes every hour and was set right at 11AM on a Monday. When…

2026

A clock loses 5 minutes every hour and was set right at 11AM on a Monday. When will it show the correct time again?

  1. A.

    11AM on Sunday

  2. B.

    11AM on Monday

  3. C.

    11AM on Tuesday

  4. D.

    11AM on Wednesday

Attempted by 3 students.

Show answer & explanation

Correct answer: A

On a standard 12-hour analog dial, a clock that drifts (gains or loses time) at a constant rate displays the correct time again only once its cumulative error reaches a full 12-hour cycle (720 minutes) — because a shift of exactly 12 hours brings the hour and minute hands back to the same face position as the correct time.

  1. The clock loses 5 minutes for every 60 minutes (1 hour) of actual elapsed time.

  2. For the clock to show the correct time again, its cumulative loss must reach a full 12-hour cycle = 12 × 60 = 720 minutes.

  3. Real time required = (720 minutes of loss) ÷ (5 minutes lost per 60 real minutes) = 720 × (60/5) = 8640 minutes.

  4. Convert to hours: 8640 ÷ 60 = 144 hours.

  5. Convert to days: 144 ÷ 24 = 6 days.

  6. Starting from 11 AM on Monday, adding 6 days lands on 11 AM the following Sunday.

Cross-check: each hour of drift costs 60 ÷ 5 = 12 real hours to accumulate, so the full 12-hour cycle takes 12 × 12 = 144 real hours — the same 6 days, confirming the result independently.

Hence, the clock next shows the correct time at 11 AM on Sunday.

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