Two finite sets have $m$ and $n$ elements. The total number of subsets of the first set is $56$ more than the total number of subsets of the second set. The values of $m$ and $n$ are
Updated On: Jul 7, 2022
m = 7, n = 6
m = 6, n = 3
m = 5, n = 1
m = 8, n = 7
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The Correct Option isB
Solution and Explanation
Let A and B be such sets, i.e, n (A) = m and n (B) = n
So, number of subsets of $A = 2^m$
Number of subsets of $B = 2^n$
According to the question,
$2^m - 2^n = 56$$\Rightarrow \, 2^n (2^{m - n} - 1) = 56 = 2^3.7$
Thus, $n = 3$ and $2^{m - n} - 1 = 7$$\Rightarrow \, n = 3$ and $m - n = 3 $
Hence, we get n = 3 and m = 6
Some important operations on sets include union, intersection, difference, and the complement of a set, a brief explanation of operations on sets is as follows:
1. Union of Sets:
The union of sets lists the elements in set A and set B or the elements in both set A and set B.
For example, {3,4} ∪ {1, 4} = {1, 3, 4}
It is denoted as “A U B”
2. Intersection of Sets:
Intersection of sets lists the common elements in set A and B.
For example, {3,4} ∪ {1, 4} = {4}
It is denoted as “A ∩ B”
3.Set Difference:
Set difference is the list of elements in set A which is not present in set B
For example, {3,4} - {1, 4} = {3}
It is denoted as “A - B”
4.Set Complement:
The set complement is the list of all elements present in the Universal set except the elements present in set A