Question

If $A=\{x\in W$ : $5<x<10\},B=\{3,4,5,6,7\}$ and $C=\{x=2n;n\in N$ and $n\le 4\}$, then find : B $\cup$ (A $\cap$ C) $=K$, then sum of each element of $K$ is,

Answer 1

Given $A=\{x\in W:5<x<10\}$, then $A=\{6,7,8,9\}$.

And $B=\{3,4,5,6,7\}$ and $C=\{x=2n:n\in N,n\le 4\}=\{2,4,6,8\}$.

Now,

$A\cap C=\{6,8\}$.

And $B\cup (A\cap C)$

$=\{3,4,5,6,7,8\}$

$=K$.

Now sum of all the elements of $K$ is $3+4+5+6+7+8=33$.