For the following questions answer them individually
For any set S let n(S) denote the number of elements in S. If A, B and C are sets such that
$$n(A \cup B \cup C) = 31, n(A) = 20, n(b) = 16, n(C) = 8, n(A \cap B \cap C') = 3, n(A' \cap B \cap C) = 2$$ and $$n(A \cap B' \cap C) = 4$$ then $$n(A \cap B \cap C) =$$
If $$P(A)$$ is the power set of the non-empty set $$A$$, define a relation $$R$$ by $$XRY$$ if and only if $$X \subseteq Y$$ for $$X,Y \epsilon P(A)$$, the relation R is not
The equation of the perpendicular bisector of the line segment joining the points (-2, 3) and (1, -2) is
For $$\alpha$$ and $$\beta$$ with $$0 \leq \alpha, \beta < \frac{\pi}{2}$$ if $$\cos \alpha = \sin \beta = \frac{1}{2}$$ then $$\alpha + 2\beta = $$