Question

If A\B = {a, b}, B\A = {c, d} and A\B = {e, f}, then the set B is equal to

• A. {a, b, c, d}
• B. {e, f, c, d}
• C. {a, b, e, f}
• D. {c, d, a, e}
• E. {d, e, a, b}

Answer 1

Answer: (B)

Given, $A / B =\{a, b\} $
$ B / A=\{C, d\} $
and $ A \cap B=\{e, f\} $
$\therefore A-B=\{a, b\}\,....(i) $
$B-A=\{c, d\}\,....(ii)$
and $A \cap B=\{e, f\} \,...(iii)$
$\therefore $ From Eqs. (i), (ii) and (iii), we get
$B=\{c, d, e, f\}$