Question

Consider the following Python code snippet. \[ A = \{\text{"this"}, \text{"that"}\}, \quad B = \{\text{"that"}, \text{"other"}\}, \quad C = \{\text{"other"}, \text{"this"}\} \] \[ \text{while "other" in C:} \] \[ \quad \text{if "this" in A:} \] \[ \quad \quad A, B, C = A - B, B - C, C - A \] \[ \quad \text{if "that" in B:} \] \[ \quad \quad A, B, C = C | A, A | B, B | C \] When the above program is executed, at the end, which of the following sets contains "this"?

• A. Only A
• B. Only B
• C. Only C
• D. A, C

Hint:

In Python, set operations such as union (\(|\)) and difference (\(-\)) can modify sets in place. The "in" operator checks whether an element exists in a set, and set operations like union and difference are commonly used for solving problems involving sets.

Answer 1

The Correct Option is B

The initial sets are \( A = \{ \text{"this"}, \text{"that"} \} \), \( B = \{ \text{"that"}, \text{"other"} \} \), and \( C = \{ \text{"other"}, \text{"this"} \} \). After executing the program and performing the set operations within the while loop, the sets are updated as follows:

\( A = \{ \text{"other"}, \text{"this"} \} \)
\( B = \{ \text{"that"}, \text{"other"}, \text{"this"} \} \)
\( C = \{ \text{"that"}, \text{"other"}, \text{"this"} \} \)

Thus, "this" is found in set \( B \) at the end of the program execution.

The correct answer is Option (B).