Please help ASAP question is in photo

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.)

Amother used 150 watts of power to raise a 15 newton object in a time interval of 8.0 seconds. through what vertical distance was the object raised ?

Two positive charges are equal. which has more electric potential energy?