Question

Which one of the following is not true

• A. $(A-B)\subseteq A$
• B. $(B^{\prime }-A^{\prime })\subseteq A$
• C. $A\subseteq (A-B)$
• D. $(A\cap B^{\prime })\subseteq A$.

Answer 1

The correct option is C $A\subseteq (A-B)$

1)$A-B$ is the part of A excluding B. This is a subset of A.
2) $B^{{}^{\prime }}-A^{{}^{\prime }}$ is $A-\left(AB\right)$. This will be a subset of A.
3)$A-B$ is the part of A excluding B. This is not a subset of A.
4)$AB=A-\left(AB\right)$. This will be a subset of A.