Brain Teasers
Mad Ade's Watch
Predictably Mad Ade is once again waiting for the "Sweaty Chef Kebab Shop" to open (he always arrives early).
In this instance he has arrived over an hour early and as a consequence stands looking at his watch and counting the seconds and minutes until the "Sweaty Chef" opens.
He noticed something odd about his watch:
The minute and the hour hand meet every 65 minutes exactly.
How much does the watch lose or gain time and by how much per hour?
In this instance he has arrived over an hour early and as a consequence stands looking at his watch and counting the seconds and minutes until the "Sweaty Chef" opens.
He noticed something odd about his watch:
The minute and the hour hand meet every 65 minutes exactly.
How much does the watch lose or gain time and by how much per hour?
Answer
The minute and the hour hand should meet 11 times in 12 hours in a normal watch i.e. they meet after every= (12 * 60) / 11 minutes
= 65.45 minutes or 65 minutes and 27.16 seconds
But in Mad Ade's case they meet after every 65 minutes, which means the watch is gaining 27.16 seconds per hour.
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Comments
A hard one. It tricked me. Nice Job.
Since the watch speeds 27,16 seconds in 65 minutes, it means 25.07 minutes in 60 minutes.
How is he timing the meeting of the hands? With another watch (or a clock) which is perfectly accurate? The teaser does not state that!
If he is timing it with the same watch, there is no way that it appears to be an interval of 65 minutes, unless it is a specially built watch with false gear ratios.
If he is timing it with the same watch, there is no way that it appears to be an interval of 65 minutes, unless it is a specially built watch with false gear ratios.
I had the same as netlett, except for 25.1 SECONDS in an hour.
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