Question

A clock seen through a mirror shows ‘quarter to seven’. What is the correct time shown by the clock?

• A. 6:15
• B. 6:17
• C. 5:17
• D. 5:15

Answer 1

The Correct Option is D

The correct time shown by the clock is 5:15.

Additional Context:

• Mirror Time Concept:
  • Mirror images show time inverted horizontally
  • Subtract the mirrored time from 11:60 to get actual time
  • Formula: Actual Time = 11:60 - Mirrored Time
• Calculation:
  • Mirrored time: "quarter to seven" = 6:45
  • 11:60 - 6:45 = 5:15
• Verification method:
  • Draw clock hands at 5:15 and check its mirror image
  • Mirror of 5:15 appears as 6:45 ("quarter to seven")
• Alternative approach:
  • For times ≤6:00, add 6 hours to mirrored time
  • For times >6:00, subtract 6 hours from mirrored time
  • 6:45 >6:00 ⇒ 6:45 - 6:00 = 0:45 (12:45) → doesn't match options
  • Thus first method is more reliable
• Common mistakes:
  • Confusing "quarter to seven" (6:45) with "quarter past seven" (7:15)
  • Using 12:00 instead of 11:60 in calculations
  • Not accounting for the exact mirror inversion principle

Correct Answer: (4) 5:15.