Ricardo of mass 80 kilogram, and Carmelita, who is lighter, is enjoying Lake Merced at dusk in a 30 kilogram canoe. When the canoe is at rest in the placid water they exchange seat, which are 3.0 meter apart and symmetrically placed with respect to the canoe's center. If the canoe moves 40 centimeter horizontally relative to a pier post. Determine what is Carmelita mass?