Question: Let U = {15, 16, 17, 18, 19, 20, 21} and A = {15, 16, 17, 18}. Find A’. Select the correct choice…

Let U = {15, 16, 17, 18, 19, 20, 21} and A = {15, 16, 17, 18}. Find A’.

Select the correct choice below and, if necessary, fill in the answer box to complete your answer.

A. A’ = { } (Use a comma to separate answers as needed.) B. A’ is the empty set.

Solution

To find \( A’ \), the complement of set \( A \) in the universal set \( U \), follow these steps: Identify the universal set \( U = \{15, 16, 17, 18, 19, 20, 21\} \). Identify set \( A = \{15, 16, 17, 18\} \). The complement \( A’ \) consists of elements in \( U \) but not in \( A \). Remove all elements of \( A \) from \( U \). The elements left are \( \{19, 20, 21\} \). Thus, \( A’ = \{19, 20, 21\} \).