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IrishJew
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23 Apr 2013, 3:24 pm

Here's a question that's actually a little more tricky than first recognized: How many times in a day does the small hand meet the big hand on a traditional clock?

:twisted: Bonus question: Give the exact time of each moment when this happens (including seconds and fractions of seconds).



ghoti
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23 Apr 2013, 4:22 pm

22 times, starting at 12:00:00, doing so once in each hour period except the 11:00 hour period



naturalplastic
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23 Apr 2013, 6:31 pm

Twenty four times:
1) midnight
2) 1:05 AM
3) 2:10 Am
4) 3;15a
5) 420
6) 525
7)630
8) 735
9) 840
10) 945
11) 1050
12)1155
13) 12 noon
14) 105 PM
15) 210 pm
16) 315pm
17)420
18) 525
19)630
20)735
21) 840
22)945
23) 1050
24) 1155 Pm

Those are the times that the big hand meets the little hand on the old style wind up type clocks- in which the hands just jump from number to number rather than sweeping constantly.

And the same times KINDA go for the modern sweep electric clocks with hands as well. Except if you wanna split hairs -on an electric clock when its say- 2:10 the hour hand is slightly past the two when the minute hand is on the ten- so though the two hands would meet at that time on a grandfather clock- that wouldnt quite meet on an electric. So you may want us to split hairs and go in for the more sophisticated arithematic to find at the EXACT time they would meet on an electric. But if thats not what you mean then I will go with the above answer.

PS:

I dont know how nor why those funky emoticons got into my answer ( the faces with the sunglasses), but they look cute so I will leave them in. They are not there to communicate anything.



physicsnut42
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25 Apr 2013, 5:55 pm

naturalplastic wrote:
I dont know how nor why those funky emoticons got into my answer ( the faces with the sunglasses), but they look cute so I will leave them in. They are not there to communicate anything.


It's because you were trying to write 8). It's happened to me before. And they are quite adorable (I have smilies disabled for this post which is why i managed to write 8) without it turning into Mr. Cool)


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Sciuridae
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25 Apr 2013, 6:15 pm

Related question:

How many times would the hour hand meet the second hand during a day?



Spiderpig
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25 Apr 2013, 6:30 pm

1438 8)

And no, “8)” is by no means the same as “8​)”.



Sciuridae
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25 Apr 2013, 6:33 pm

That is correct, I believe.

The 8) and "8)" thing should be better, haha.



IrishJew
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26 Apr 2013, 2:19 pm

Naturalplastic: I guess I should have specified that I meant the type of clocks whose minute hand sweeps through constantly. So I guess technically you're right.

But for an "analog" traditional clock, if you will, here's the trick: When you remember that the big hand does not meet the little hand for the 11th hour (because by the time it does, it's already 12:00:00), then you realize that the two hands meet only 11 times every 12 hours. Thus, you divide 12 hours by 11 to get 12/11th's of an hour, which is 1 and 1/11th hour, which is 1 hour, 5 and 5/11th minutes, which is 1 hour 5 minutes and 27 3/11 seconds. Add this to 12:00:00 11 times to get:

1:05:27 3/11
2:10:54 6/11
3:16:21 9/11
4:21:49 1/11
5:27:16 4/11
6:32:43 7/11
7:38:10 10/11
8:43:38 2/11
9:49:05 5/11
10:54:32 8/11
12:00

8)