What is the probability that the product of the integers from n-2 to n+2 are also a product of 10 if n∈{13,14,15,16,17}?

For Example
If n was 13 then the product would be 11*12*13*14*15

I want an answer that does not use brute force.


The probability is $1$, because every $5$ consecutive numbers must contain a multiple of $5$ and a multiple of $2$, whence the product is a multiple of $10$ (because $5$ and $2$ are co-prime).

  • $\begingroup$ That is correct $\endgroup$ – Ethan Yun Oct 24 '17 at 2:07
  • $\begingroup$ @EthanYun are you testing my ability? Question downvoted. $\endgroup$ – Kenny Lau Oct 24 '17 at 2:10

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