xjo weekend zoomba lounge, page-68

Yotta and bluesdog, (and anyone else interested), one for you:

An adventurer sets out from his tent one morning and walks ten kilometers due south then ten kilometers due west then ten kilometers due north, and he arrives, somewhat exhausted, back at his tent.

(1) (easy - 1 mark) Where did he pitch his tent?

(2) (difficult - 9 marks) Additionally, there are many other locations on the Earth’s surface where he could have pitched his tent and followed the same directions and arrived back at his tent. Where are these other locations?

There are no catches or gotchas, and as far as I know this could be done in real life, so assume the Earth is a simple smooth perfect sphere.