For every $n, m \in \mathbb{N}; n,m > 1$, construct a method to produce $\lfloor\frac{n}{2}\rfloor$ using n ms.

You can use: $$x+y$$ $$x-y$$ $$x*y$$ $$\frac{x}{y}$$ $$x^y$$ $$x\bmod y$$ $$\sqrt[k]{x} : k \in \mathbb{N}$$ $$x!$$

I can't think of anything else now off the top of my head, but you get the general gist.


Yes, I mean to write something which tells you how to write an equation to form n/2 with n m's, it doesn't matter what n is or m is, it MUST work!

  • $\begingroup$ When you say that it doesn't matter what n or m is, do you mean it must work for all m and n, or do you mean that the answerer is free to choose any convenient m and n? (E.g. I choose n=2 and any non-zero m, and we can get n/2 = m/m = 1.) $\endgroup$ – Lawrence Mar 1 '16 at 9:38
  • $\begingroup$ It's easy for even $n$. just do $m/m + m/m + ...$ until you have $n m$s. not sure about odd $n$. $n = 1$ probably is impossible $\endgroup$ – Ivo Beckers Mar 1 '16 at 9:44
  • $\begingroup$ @Lawrence Must work for all. $\endgroup$ – user3836103 Mar 1 '16 at 9:46

With the new rules, my m/m idea and Ivo Beckers' continuation:

For even $n$: $\frac{n}{2} = \frac{m}{m} + \frac{m}{m} + ...$.

For odd $n$: change the first term to $\frac{\sqrt{m}\sqrt{m}}{m}$.

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  • $\begingroup$ @IvoBeckers probably the same reason I didn't think of extending the m/m idea :) . $\endgroup$ – Lawrence Mar 1 '16 at 10:04

This is easy

For even $n$ do $\frac m m + \frac m m + ...$ until you have $n m$s.

EDIT odd n is still incorrect, will fix it when i know a solution
For odd $n$ do $\frac {m+m} m + \frac m m + \frac m m + \frac m m ...$

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  • $\begingroup$ +1, but this doesn't form 4 with 5 ms (see the OP's edited example). Probably a typo in the question. $\endgroup$ – Lawrence Mar 1 '16 at 9:55
  • $\begingroup$ @Lawrence yeah you're right. It's a bit unclear what the OP is asking I guess. $\endgroup$ – Ivo Beckers Mar 1 '16 at 9:57
  • $\begingroup$ Yeah, it should form 2 with 5ms. $\endgroup$ – user3836103 Mar 1 '16 at 9:58

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