What is the easiest way to put a percentage into a fraction

News cameras take an overhead picture of a crowd at an outdoor event journalist then count the total number of people in the picture and use the sample of estimate the total number of people in the crowd this process is an example of

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

If the slope of one line equals the slope of another line then ? a) the two lines are intersecting lines b) the two lines are perpendicular lines c) the two lines are parallel lines d) the two lines always have very steep slopes