Archimedes' Principle 3?

An 78.8-kg person is wearing a life jacket and floating in water. The life jacket has a volume of 3.0 x 10-2 m3 and is completely submerged under the water. The volume of the person's body that is underwater is 6.2 x 10-2 m3. What is the density of the life jacket? ume that the person's density is equal to that of water.