Devin investigated whether salt reduces the boiling point of water. She poured 1 gallon of 18 degrees Celsius (°C) water into a pot and added 2 cups of salt to it. Devin heated it over a fixed flame and measured the temperature when the water reached a rolling boil. She repeated the experiment with 1 gallon of water and 4 cups of salt under identical conditions. Where did Devin make a mistake in her experimental design?

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)