You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?
Three friends decide to distribute the soda cans they had among them. When all of them had drunk four cans each, the total number of cans that remained was equal to the cans each one of them had after they had divided the cans.
Can you calculate the total number of cans before distribution?