Each of 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 their boards of directors, then how many distinct persons serve on one or more boards of directors?\nOptions:\n(A) 8\n(B) 13\n(C) 16\n(D) 24\n(E) 27 Hmmm, my stream of consciousness:
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A intersect B intersect C = 4\nA intersect B but not C = 1\nB intersect C but not A = 1\nC intersec A but not B = 1\nA only is 2; B only is 2; C only is 2\nTherefore, total 13 members serve on one or more boards of directors. So, the answer is (B).
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