premise: During the last week of March , I had my spring break . We did n't go anywhere new nor did we do something everyday but it was nice to be able to not worry about going to class . However , our friend Mike 's birthday happened to fall during spring break so we got a chance to celebrate that with him . We also went to Las Vegas , the grand Sin City . What 's a possible reason they went to Las Vegas ?
hypothesis: Because they did n't worry about going to class .