Advertisements
Advertisements
Question
If A and B are two sets such that \[n \left( A \right) = 20, n \left( B \right) = 25\]\text{ and } \[n \left( A \cup B \right) = 40\], then write \[n \left( A \cap B \right)\]
Advertisements
Solution
We have:
\[n\left( A \right) = 20, n\left( B \right) = 25 \text{ and } n\left( A \cup B \right) = 40\]
We know:
\[n\left( A \cup B \right) = n\left( A \right) + n\left( B \right) - n\left( A \cap B \right)\]
\[ \Rightarrow n\left( A \cap B \right) = n\left( A \right) + n\left( B \right) - n\left( A \cup B \right)\]
= 20 + 25
\[-\] 40
= 5
APPEARS IN
RELATED QUESTIONS
Make correct statement by filling in the symbols ⊂ or ⊄ in the blank space:
{2, 3, 4} _____ {1, 2, 3, 4, 5}
{1, 2, 3} ⊂ {1, 3, 5}
{a} ⊂ {a. b, c}
{a} ∈ (a, b, c)
Let A = {1, 2, {3, 4}, 5}. The following statement is correct or incorrect and why?
{3, 4} ⊂ A
Write down all the subsets of the following set:
{a}
Write the given intervals in set-builder form:
(–3, 0)
Write the given intervals in set-builder form:
[6, 12]
Write the following interval in set-builder form:
[–23, 5)
Determine whether the statement is true or false. If it is true, prove it. If it is false, give an example.
If A ⊂ B and x ∉ B, then x ∉ A
If a set contains n elements, then write the number of elements in its power set.
If \[A = \left\{ \left( x, y \right) : y = e^x , x \in R \right\} and B = \left\{ \left( x, y \right) : y = e^{- x} , x \in R \right\}\]write\[A \cap B\]
The number of subsets of a set containing n elements is
If A = |1, 2, 3, 4, 5|, then the number of proper subsets of A is
In set-builder method the null set is represented by
Make correct statement by filling in the symbols ⊂ or ⊄ in the blank space:
{x : x is a student of Class XI of your school} ____ {x : x student of your school}
Make correct statement by filling in the symbols ⊂ or ⊄ in the blank space:
{x : x is a circle in the plane} _____ {x : x is a circle in the same plane with radius 1 unit}
Make correct statement by filling in the symbols ⊂ or ⊄ in the blank space:
{x : x is a triangle in a plane} _____ {x : x is a rectangle in the plane}
Make correct statement by filling in the symbols ⊂ or ⊄ in the blank space:
{x : x is an equilateral triangle in a plane} _____ {x : x is a triangle in the same plane}
Make correct statement by filling in the symbols ⊂ or ⊄ in the blank space:
{x : x is an even natural number} _____ {x : x is an integer}
Let A = {1, 2, {3, 4}, 5}. The following statement is correct or incorrect and why?
{1, 2, 3} ⊂ A
Let A = {1, 2, {3, 4}, 5}. The following statement is correct or incorrect and why?
Φ ∈ A
Let A = {1, 2, {3, 4}, 5}. The following statement is correct or incorrect and why?
Φ ⊂ A
Write the following interval in Set-Builder form:
(– 3, 0)
State true or false for the following statement given below:
Q ∩ R = Q, where Q is the set of rational numbers and R is the set of real numbers.
If X = {1, 2, 3}, if n represents any member of X, write the following sets containing all numbers represented by n + 6
If X = {1, 2, 3}, if n represents any member of X, write the following sets containing all numbers represented by `n/2`
If X = {1, 2, 3}, if n represents any member of X, write the following sets containing all numbers represented by n – 1
If Y = {1, 2, 3, ... 10}, and a represents any element of Y, write the following sets, containing all the elements satisfying the given conditions.
a ∈ Y but a2 ∉ Y
If X = {8n – 7n – 1 | n ∈ N} and Y = {49n – 49 | n ∈ N}. Then ______.
State True or False for the following statement.
If A is any set, then A ⊂ A.
State True or False for the following statement.
Given that M = {1, 2, 3, 4, 5, 6, 7, 8, 9} and if B = {1, 2, 3, 4, 5, 6, 7, 8, 9}, then B ⊄ M.
State True or False for the following statement.
The sets {1, 2, 3, 4} and {3, 4, 5, 6} are equal.
