I'm guessing he/she already has his mind made up and just wants one person to confirm it's possible. It is possible for a very short term arrangement. I emphasize short term (QT period, transition while you get a larger setup going, etc.). It will do you and the fish no good to do this though. In the end, you will have a tang that probably will not behave very well and live a shortened existence and you'll just be frustrated. Get at least a 4 foot long tank (75G is smallest?). Even then, the list of tangs you can keep is pretty short (maybe only a yellow). Bear in mind, though he is one of the most peaceful species, he's still a bully and will not take kindly to having too many others in these cramped quarters.