[" choice of "5" different buses and "4" trains to return.In how many ways can he "],[" perform his journey? "],[" Eight children are standing in a queue."],[" (i) In how many way can the queue be formed? "],[" (ii) How many arrangements are possible if the tallest child stands at the end "],[" of the queue? "],[" In how many ways can a student answer a set of ten true/false type questions? "]