Question

The table shows the performance of a selection of 113 stocks after one year. (Take S to be the set of all stocks represented in the table. If a stock stayed within 20% of its original value, it is classified as "unchanged".)

	Companies			Total
	Pharmaceutical P	Electronic E	Internet I
Increased V	12	5	16	33
Unchanged N	33	0	14	47
Decreased D	12	5	16	33
Total	57	10	46	113

Compute

n(P ∪ N').

What does this number represent?

n(P ∪ N') is the number of stocks that were either pharmaceutical stocks, or were unchanged after a year (or both).n(P ∪ N') is the number of stocks that were either not pharmaceutical stocks, or were not unchanged after a year (or both).     n(P ∪ N') is the number of stocks that were either pharmaceutical stocks, or were not unchanged after a year (or both).n(P ∪ N') is the number of stocks that were pharmaceutical stocks and were not unchanged after a year.n(P ∪ N') is the number of stocks that were not pharmaceutical stocks and were unchanged after a year.

Answer 1

n(P U N') = 113 - P(P N) = 113 - 33 = 80

n(P ∪ N') is the number of stocks that were either pharmaceutical stocks, or were not unchanged after a year (or both).