Question

If A and B are two disjoint sets, then A - B = ______.

• A. $\frac{}{A\cap B}$
• B. $A\cap \overline{B}$ .
• C. $\overline{A}\cap \overline{B}$ .
• D. $\overline{A}\cap B$

Answer 1

The correct option is B

$A\cap \overline{B}$ .

A and B are disjoint sets (given).

The shaded portion represents A - B, i.e., only A.

Let us draw the venn diagrams to represent the options

By observing the Venn diagrams we find

$A\cap \overline{B}=A-B$

Note: $A\cap \overline{B}$ are the elements belonging to A and $\overline{B}$ (outside B) which is nothing but only A or A - B.

Hint: $\overline{B}$ are the elements outside B.