Question

3. Let A and B be two sets such that n(A)=20, n(AUB)=41, n(AnB)=2
:
find n(B), n(A-B) and n(B-A)
Plz today is my paper send me answer

Answer 1

Answer:

Given ,

• n(A) =20
• n(AUB) =41
• n(A∩B) =2

We know that ,

$\underline {\underline{ \bold{n(AUB) = n(A) + n(B) - n(A∩B)</p><p>}}}$

$\bold \color{blue} { \implies41 = 20 + n (B) - 2}$

$\bold \color{blue} { \implies n (B) = 41 - 18}$

$\bold \color{green} { \implies \boxed {\bold{n (B) = 23}}}$

Again , we also know that

$\underline{ \underline{ \bold {n(A) = n(A-B) + n(A∩B)}}}$

$\color{blue} \bold{ \implies20 = n (A-B ) + 2}$

$\color{green} \bold{ \implies \: \boxed{ \bold{ n (A-B ) = 18}}}$

And

${ \underline {\underline \bold{n(B) = n (B- A) + n(A∩B)}}}$

$\color{blue} \bold{ \implies \: 23 = n (B-A) + 2}$

$\color{green} \bold{ \implies \: \boxed{\bold{n (B-A) + = 21}}}$