where in the world can you see the sun set and rise at the same time?

Answer 1

On the arctic circle at the summer solstice, or the antarctic circle on the winter solstice. On those days the sun just touches the horizon and essentially both sets and rises at the same time.

Answer 2

Close, but no cigar.

On either the arctic OR antarctic circle at WINTER solstice only (both hemispheres -- since winter down south begins in June);

OR

Anywhere within the arctic and antarctic circles (except the poles), twice a year, with exact dates dependent on your latitude.