A student has two identical sheets of paper he crumbles one up into a small ball if he drops the sheet of paper and a ball wallpaper off a building at the same time which will reach the ground frirst?

Both the sheet of paper and the crumpled ball of paper will reach the ground at the same time. This is because the shape or size of an object does not affect the rate at which it falls in the absence of air resistance, as demonstrated by Galileo in his Leaning Tower of Pisa experiment.