# A travesty of upvoting

The most upvoted solution, which has 13 upvotes, is nice, short, and intuitive, but not rigorous. The best rigorous solution has 3 upvotes while mine, which is more complete has 1.

Not really whining, but something seems wrong with the upvote system.

EDIT: He said: 2^1 ends in 2 2^2 ends in 4 2^3 ends in 8 2^4 ends in 6 2^5 ends in 2 2^4k ends in 6.

Why does 2^4k end in 6? It is not explained at all.

• Welcome to SE! This is how it works. :-) – quid Dec 14 '14 at 2:12
• I don't think Fermat's Little Theorem is required to tell that $2^4$ is congruent to $1$ modulo $5$, or that $6 \times 6 = 36$ which also ends in $6$. There is rigor, and then there is unneeded rigor... – Carl Mummert Dec 14 '14 at 2:16
An aside: with a username that contains the term "troll," you may find that people aren't too sympathetic when you complain. :)