The range of $f(x) = \cos 2x - \sin 2x$ contains the set

There are $80$ families in a small extension area. $20$ percent of these families own a car each. $50$ percent of the remaining families own a motor cycle each. How many families in that extension do not own any vehicle?

Of the members of three athletic teams in a school,$21$ are in the cricket team,$26$ are in the hockey team,and $29$ are in the football team. Among them,$14$ play hockey and cricket,$15$ play hockey and football,and $12$ play football and cricket. Eight play all the three games. The total number of members in the three athletic teams is:

If the sets $A$ and $B$ are defined as $A = \{ (x, y) : y = \frac{1}{x}, x \in R, x \neq 0 \}$ and $B = \{ (x, y) : y = -x, x \in R \}$,then:

If $A = \{a, d\}, B = \{b, c, e\}$ and $C = \{b, c, f\},$ then $A \times (B \cap C) =$

Domain of the function $f(x) = \sqrt{2 - 2x - x^2}$ is