skip to main content




Puzzle ZHBL 



??

I recently gave a new carriage clock to my friend for a very special birthday.

However, as usual with my presents, it was quite useless as it loses 6 minutes every hour.

I set it using my own accurate clock at midnight and the clock now shows 10.12am.

I know that it stopped 2 hours ago, so what is the correct time now?

Puzzle Copyright © Kevin Stone

workings hint hide answer print

Share Link — www.brainbashers.com/puzzle/zhbl

Answer
1.20pm.

Reasoning
The clock is losing 6 minutes every hour, for every real hour that has passed the clock will only show 54 minutes.

The clock shows 10.12am, so we know that 612 clock minutes have passed.

Therefore, 612 ÷ 54 x 60 = 680 real minutes have passed, which is 11 hours and 20 minutes (11.20am).

The clock stopped 2 hours ago, therefore the time is now 1.20pm.

 

Note: BrainBashers has a Dark Mode setting.