If n(X) = mC6, then the value of m is ______.
Correct Answer :
Solution :
The correct answer is 20.
To find the value of in the given equation, we need to analyze the underlying mathematical context of this problem, which is typically defined as follows:
Let be a set. Let be the set of all relations from to such that:
1. has exactly 6 elements (ordered pairs).
2. For each ordered pair , the condition is satisfied.
We want to find , which is the total number of such relations.
Step 1: Determine the total number of ordered pairs in
The number of elements in set is 6. Thus, the total number of ordered pairs in the Cartesian product is:
Step 2: Count the ordered pairs that do NOT satisfy the condition
The pairs that do not satisfy the condition are those where:
This means either or .
Case 2.1: (i.e., )
These are the diagonal elements. There are 6 such pairs:
Total = 6 pairs.
Case 2.2:
These are the pairs of consecutive elements:
- If , the pairs are: (5 pairs)
- If , the pairs are: (5 pairs)
Total = pairs.
Summing the excluded pairs:
Step 3: Calculate the number of allowed pairs
Subtracting the excluded pairs from the total pairs:
Step 4: Find the number of relations in
A relation in is formed by choosing exactly 6 ordered pairs from the 20 allowed pairs. Therefore, the number of such relations is given by the combination formula:
Step 5: Determine
Comparing the expression to the given equation , we have:
This directly gives:
Access expert-curated educational resources and study materials—completely free.
Create, conduct, and manage professional online assessments with Mindyard. Perfect for teachers and institutes.
Copyright © 2026 Mindyard. All Rights Reserved.