Sunday, July 10, 2011

Overlap in the clock

How many times the hands will overlap in a clock? 22. why?

12 is the first
1am will not overlap at 1.05 but a bit later (because when you get 5min, the 1 has already moved a bit)
2am will not overlap at 2.10 but a bit later (because when you get 5min, the 1 has already moved a bit more)
11am is the last one and this point of overlap is very close to 12

So out of 12, there are 11 points of overlap. In 24hours are 22, with 2 "missing".

How much is a bit more? 1/11  because they are uniformly distributed

So 12, 1+1/11, 2+2/11, 3+3/11

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