looping through possible combinations of McNuggets packs of 6,9 and 20

[gslindstrom]

On Aug 12, 4:33 am, Paul Rubin <no.em... at nospam.invalid> wrote:
> Baba <raoul... at gmail.com> writes:
> > exercise: given that packs of McNuggets can only be bought in 6, 9 or
> > 20 packs, write an exhaustive search to find the largest number of
> > McNuggets that cannot be bought in exact quantity.
>
> Is that a homework problem?  Hint: first convince yourself that a
> largest number actually exists.

If I recall, this was a "puzzler" on the NPR radio show "Car Talk".
Still might be homework, though.