Question

A clock is set right at $4:00$ a.m. on Sunday. The clock loses $20$ minutes in $24$ hours. What will be the correct time when this clock indicates $3:00$ a.m.on Wednesday?

Answer 1

Time from 4:00 a.m. on Sunday to 3:00 a.m. on Wednesday =24×3−1=72−1=71=24×3−1=72−1=71 hours.
Now, 23 hours 40 minutes of this clock = 24 hours of correct clock.
2323=7132323=713 hours of this clock = 24 hours of correct clock.
So, 71 hours of this clock =24×3×7171=72=24×3×7171=72 hours of correct clock.
Therefore, the correct time is 3:00 a.m. + (72 -71) = 4:00 a.m.