A sailor on a trans-Pacific solo voyage notices one day that if he puts of fresh water into a plastic cup weighing , the cup floats in the seawater around his boat with the fresh water inside the cup at exactly the same level as the seawater outside the cup (see sketch at right).
Calculate the amount of salt dissolved in each liter of seawater. Be sure your answer has a unit symbol, if needed, and round it to significant digits.