Find the following. n(B ∪ C)

Question

Let U = {English, French, History, Math, Physics, Chemistry, Psychology, Drama}, A = {French, Math, Physics, Drama},

 B = {Chemistry, Psychology, History, Physics, Drama},

 and C = {English, Math, History}.

 Find the following.

n(B ∪ C)

Answer 1

The symbology n(B ∪ C) means to find the number of elements in the union of set B with set C.

Since set B = {Chemistry, Psychology, History, Physics, Drama} and set C = {English, Math, History}, the union of B and C is  B = {Chemistry, Psychology, History, Physics, Drama ,English, Math, History} but this has a duplicate in it.

Removing the duplicate, we have B ∪ C = {Chemistry, Psychology, History, Physics, Drama, English, Math}.

So the number of elements in the set is 7