Discrete Math: new drug tested on 200 patients w/ high press

[archy]

A new drug was tested on a group of 200 patients with high blood pressure. By the end of the trial period, 90 patients showed improvement from the drug, 35 patients developed side effects, and 95 patients showed no improvement and had no side effects. How many patients showed improvement and had side effects?

 

[arthur ohlsten]

Re: Discrete Math

sketch 2 overlapping circles, mark one I with 90 inscribed. mark the second S with 35 inscribed mark area outside 95

now sum the numbers
total = 95+90+25= 220
but only 200 samples should exist. We counted 20 patients twice. they must be in overlapping area
change the figure to have 70 in I , 20 in overlap area , 15 in S , and 95 outside the circles.
20 patients had improvement and side effects
Arthur