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 The strange clock (Posted on 2004-02-17)
I have a very strange clock. At first glance, it looks like a normal clock with three hands and the numbers 1 through 12 all around. The only differences are that the hands are indistinguishable from each other and they are faster. One hand completes a circle in 3 minutes, another in 4 minutes, and the last in 6 minutes. They all go clockwise.

One morning, when I looked at the clock, the hands were all pointing exactly at the numbers 1, 2, and 3.
Later that day, I saw that the three hands were pointing exactly at 6, 10, and 11.

Can you identify which hands I saw each time? Prove it.

 Submitted by Tristan Rating: 2.6667 (6 votes) Solution: (Hide) I will call the hands A, B, and C, from fastest to slowest. So A goes around in 3 minutes, B in 4, and C in 6. This puzzle only deals with integer minutes, because all hands point directly at numbers only every minute. Hand B has only three possibilities. It could have moved from 1 to 10, 2 to 11, or 3 to 6. The number of minutes it takes mod 4 is 1 or 3. Hand C, in that time could have moved 2,6, or 10 numbers over in that time. The only possibility left considering this is from 1 to 11. Hand B is left only with the possibility of 3 to 6, and hand A goes from 2 to 10. So this is what happened: Hand A went from 2 to 10, Hand B went from 3 to 6, Hand C went from 1 to 11, The time this took mod 12 is 5.

 Subject Author Date Yeppers John 2004-02-24 23:59:07 Solution sherif 2004-02-23 18:51:19 I think me knows it! Mitch Mullings 2004-02-22 19:59:31 i think i got it :) evan 2004-02-21 03:08:57 unique solution pierre 2004-02-19 14:44:58 re(3): Solution Charlie 2004-02-18 15:31:10 re(2): Solution Mital 2004-02-18 13:12:58 re: Solution SilverKnight 2004-02-18 12:59:10 Solution Mital 2004-02-18 12:57:35 my solution -no calculators Ady TZIDON 2004-02-18 03:49:37 Solution Gabe 2004-02-17 13:03:22 solution Charlie 2004-02-17 11:46:54 Solution Wengel 2004-02-17 10:54:36

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