The part to feel guilty about is that I chose not to explain that the salesman is probably either lying, or insane, or both, and therefore probably shouldn’t be considered “a trusted friend”. And also that I chose to just try to avoid both of these people, rather than… thinking of a less blatantly unfriendly solution.
I’m going to go ahead and post the spoiler, rot13′d
Zl thrff: Ur’f ylvat. Naq ur’f cebonoyl ylvat gb uvzfrys nf jryy, va beqre sbe gur yvr gb or zber pbaivapvat. Gung vf, qryvorengryl sbetrggvat nobhg gur pyvragf jub unir qvrq.
Vs ur unf unq a pyvragf, naq vs gurve nirentr ntr vf 30… Rnpu lrne, gur cebonovyvgl bs rnpu bs gurz fheivivat gur arkg lrne vf, jryy, yrg’f ebhaq hc gb 99%. Gung zrnaf gung gur cebonovyvgl bs nyy bs gurz fheivivat vf 0.99^a. Rira vs ur unf bayl unq 100 pyvragf, gura gur cebonovyvgl bs gurz nyy fheivivat bar lrne vf 0.99^100=0.36 Vs ur unq 200 pyvragf, gura gur cebonovyvgl bs gurz nyy fheivivat bar lrne vf 0.99^200=0.13. Naq gung’f whfg sbe bar lrne. Gur sbezhyn tbrf rkcbaragvny ntnva vs lbh pbafvqre nyy 20 lrnef. Gur cebonovyvgl bs nyy 100 pyvragf fheivivat 20 lrnef vf 0.99^100^20=1.86R-9
Naq zl npghny erfcbafr vf… qba’g ohl gur yvsr vafhenapr. Ohg qba’g gryy nalbar gung lbh guvax ur’f ylvat. (hayrff lbh pbhag guvf cbfg.) Nyfb, gur sevraq ab ybatre pbhagf nf “gehfgrq”, be ng yrnfg abg gehfgrq gb or engvbany. Bu, naq srry ernyyl thvygl sbe abg svaqvat n orggre fbyhgvba, naq cbfg gb YJ gb frr vs nalbar guvaxf bs n orggre vqrn. Ohg qba’g cbfg rabhtu vasbezngvba sbe nalbar gb npghnyyl guvax bs n orggre fbyhgvba. Naq vs fbzrbar qbrf guvax bs n orggre vqrn naljnl, vtaber vg vs vg’f gbb fpnel.
I don’t understand what you mean by a better solution; I wouldn’t feel guilty about doing what you did.
The part to feel guilty about is that I chose not to explain that the salesman is probably either lying, or insane, or both, and therefore probably shouldn’t be considered “a trusted friend”. And also that I chose to just try to avoid both of these people, rather than… thinking of a less blatantly unfriendly solution.