yes, i think the single guy is right. it should be divided by 3. couple living together in one bed does not mean that they can pay only one's rent. The question here is whether the rent is shared between the number of rooms or the number of people. if it is number of room then the single guy has a right to share his room with another friend and charge him for rent and keep the money in pocket. if its with the number of people, then since its three it should be divided by three.