Question

Let $U=\left\{1,2,3,4,5,6,7,8,9\right\},A=\left\{1,2,3,4\right\},B=\left\{2,4,6,8\right\}$ and $C=\left\{3,4,5,6\right\}$. Find $(B-C)\text{'}$

Answer 1

Compute the required value.

Given: $U=\left\{1,2,3,4,5,6,7,8,9\right\},A=\left\{1,2,3,4\right\},B=\left\{2,4,6,8\right\}$ and $C=\left\{3,4,5,6\right\}$

So,

$\left(B-C\right)=\left\{2,4,6,8\right\}-\left\{3,4,5,6\right\}$

$\Rightarrow$$(B-C)=\left\{2,8\right\}$

Since,

$\left(B-C\right)\text{'}=U-(B-C)$

$\Rightarrow$ $\left(B-C\right)\text{'}=\left\{1,2,3,4,5,6,7,8,9\right\}-\left\{2,8\right\}$

$\Rightarrow$ $\left(B-C\right)\text{'}=\left\{1,3,4,5,6,7,9\right\}$

Hence, the value of $(B-C)\text{'}$is $\left\{1,3,4,5,6,7,9\right\}$.