Physics, buoyancy problem? please help!!!!!?

You first convert their weight in pounds to grams. Divide their m in grams by their density and that will give you their volume. Next comes the physics part, the buoyancy law states that a body in a fluid is supported by a force equal to the weight of the displaced fluid. So the submerged person will weight less by the amount of the displaced water since the density of water is 1 gram/cm3 the volume of the person will equal their buoyant force in pounds. then all you have to do is convert the buoyant force from grams to pounds and subtract it from the weight in air and you are done.