Question 9 of 35intermediate🔍 AnalyzeShort Answer2 marks

Let AA and BB be two sets such that n(A)=3n(A) = 3 and n(B)=2n(B) = 2. If (x,1),(y,2),(z,1)(x, 1), (y, 2), (z, 1) are in A×BA \times B, find AA and BB, where x,yx, y and zz are distinct elements.

Correct Answer

A = {x, y, z} and B = {1, 2}

Exercise: EXERCISE 2.1 | Q: 9 | (Page 4)
For More Understanding

Explanation

This question tests the understanding of Cartesian products. From Example 6 in the textbook, we learn that for any Cartesian product A × B, set A consists of all first elements of the ordered pairs, and set B consists of all second elements. Given the ordered pairs (x, 1), (y, 2), (z, 1) in A × B, we extract the first elements {x, y, z} to form set A, and the second elements {1, 2} to form set B. The conditions n(A) = 3 and n(B) = 2 are satisfied since A has exactly 3 distinct elements (x, y, z are distinct) and B has exactly 2 distinct elements (1 and 2).

Solution Steps

  1. Step 1: From the ordered pairs (x, 1), (y, 2), (z, 1) in A × B, identify the first elements: x, y, z

  2. Step 2: Identify the second elements: 1, 2, 1

  3. Step 3: Set A = set of first elements = {x, y, z} (since x, y, z are distinct, n(A) = 3 ✓)

  4. Step 4: Set B = set of second elements = {1, 2} (n(B) = 2 ✓)