Answer
n($ P^{\prime}\cup$N )=80
(number of of stocks that are either not pharmaceutical or have not changed in value)
Work Step by Step
$ P^{\prime}\cup$N is the set of stocks that are either not pharmaceutical or have not changed in value.
Cardinality of union: n($ P^{\prime}\cup$N )= n($P^{\prime}$) +n(N) -n($ P^{\prime}\cap$N)
n($P^{\prime}$)=n(S)-n(P)= 100 - 50 = 50
n(N)= 40
n ($ P^{\prime}\cap$N)= 0+10 (in row N, all that are not P)
n($ P^{\prime}\cup$N )=50+40-10=80
n($ P^{\prime}\cup$N )=80
