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Six numbers and a prime (Posted on 2006-08-29) Difficulty: 2 of 5
Consider six consecutive positive integers. Show that there is a prime number that divides exactly one of them.

See The Solution Submitted by JLo    
Rating: 3.0000 (1 votes)

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re: Proof | Comment 4 of 23 |
(In reply to Proof by Tristan)

It's not quite true that exactly 5 of the numbers are divisble by 2, 3, or 5. It is possible that 2 of the numbers can be divisible by none of 2, 3, or 5: for example (15, 16, 17, 18, 19, 20) has 2 numbers that are primes bigger than 5.

I don't think this really affects your proof, however, because what seems to be important is that at least one of the numbers is not divisible by 2, 3, or 5, and that is true.

  Posted by Richard on 2006-08-29 19:29:21

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