Give Alex exactly 100 marbles on a plate and an eggcup full of tepid water
Give Alex exactly 100 marbles on a plate and an eggcup full of tepid water. One of you must always be sitting down, one of you must always be jumping and one of you must always be clapping your hands. You must each change your action every 30 seconds and no-one may hold anything for more than five seconds at a time. Fastest wins. Your time starts now.