Five students went for a hiking trip.each of them were carrying separate bags of 15/4kg Of Rice,19/8kg of fuel and 9/2kg of other provisions.they got a man to help them carry the bags. But he could carry a maximum weight of 42kg.the students decided to use him and also decided that each of them will carry one of their bags.which of the three bags will each one of them have to carry?why?