perplexus.info :: Numbers : Prime times

Prime times (Posted on 2011-03-18)

3:53 is a prime time because 353 is prime.
1. How many prime times are there in 12 hours?
2. How many prime times are there in 24 hours?

See The Solution Submitted by Math Man

Rating: 4.0000 (1 votes)

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Puzzle Answer

Comment 2 of 2 |

First Part

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The 12 hour case envisages the times between 1:00 to 12:59 inclusively, where there are precisely 111 prime times.

Second Part

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The 24 hour case envisages the times between 0:00 to 23:59 inclusively, where there are precisely 211 prime times.

Posted by K Sengupta on 2022-08-29 22:34:33

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