A diligent student has a slow leak in her bike tire, but has been too busy studying for exams
to fix it. We’ll assume that the pressure in the tire decreases at a rate proportional to the
difference between the atmospheric pressure (15 lbs.) and the tire pressure. Monday at
6:00 pm she pumped up the pressure to 85 lbs. By 6:00 pm Tuesday it was down to 75 lbs.
When does she need to pump up the tire if she wants to keep the pressure at a minimum of
40 lbs.? Give the day and time.