Each of the three charities in Novel Grove Estates has 8 persons serving on its board of directors. If exactly 4 persons serve on 3 boards each and each pair of charities has 5 persons in common on the their boards of directors, then how many distinct persons serve on one or more boards of directors?
A) 8
B) 13
C) 16
D) 24
E) 27
The answer says to make a chart, using letters to represent the different board members. Can anyone explain their process for setting up a chart like that? Thanks!
A) 8
B) 13
C) 16
D) 24
E) 27
The answer says to make a chart, using letters to represent the different board members. Can anyone explain their process for setting up a chart like that? Thanks!
