I've stared at this poster while waiting for my train in the morning almost every day for the last three weeks. If you can't see the image, it's a poster for a new programme on Dave (a comedy tv channel) with Dara O Briain called The School of Hard Sums. It has this written on it:
You are waiting for a train.
It is 12:01 exactly. Trains arrive every time the minute hand lies on top of the hour hand.
How long do you have to wait until the next train (If it's on time!)?
I have had the following reactions to this poster, chronologically:
1:05. So a wait of 1 hour 4 minutes.
Dara, that isn't even "sums", it's imagining a clock face.
Is this a trick question? Am I missing something?
Ok, fine, it might be slightly after, but I don't think the hour hand would move far enough in five minutes to be significant.
Five minutes is 1/12 of an hour; five minutes divided by twelve is 25 seconds.
1:05:25, Dara, that's as precise as I'm willing to get.
Unless you want to count the little bit for however many nanometers the hour hand would move ahead in 25 seconds.
I mean, I don't even know the specifications of this hypothetical clock! Maybe it's one of those ones that ticks over every minute, instead of moving smoothly. And I don't know the width of the hands, either.
You have to give me more details here, Dara.
Just put a new riddle up already.
... I still don't really want to watch this programme.