pretty much the previous poster has it i spose
for a short workout id probably go bodyweight. depends if youre trying to drop weight or gain muscle? and are you male or female?
if youre trying to burn fat, go for a run/bike/swim etc
if youre trying to gain muscle, try the old pushups/chinups/situps routine of old. if you can find something to use for a chinups bar. then go for a run after that