Taking the set of natural numbers as the universal set, write down the complements of the following sets: (ix) $\{ x : 2x + 5 = 9\}$

If $X= \{ a, b, c, d \}$ and $Y = \{ f, b, d, g\}$, find (i) $X – Y$

Make correct statements by filling in the symbols $\subset$ or $\not\subset$ in the blank spaces : (vi) \{$x : x$ is an equilateral triangle in a plane\} . . . \{$x : x$ is a triangle in the same plane\}

If $A = \{ 3, 5, 7, 9, 11 \}$, $B = \{7, 9, 11, 13\}$, $C = \{11, 13, 15\}$ and $D = \{15, 17\}$; find (iii) $A \cap C \cap D$

Let $A = \{1, 2, 3, 4, 5, 6\}$. Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces: (vi) 10. . .A

Draw appropriate Venn diagram for each of the following : (ii) $A′ \cap B′$

Taking the set of natural numbers as the universal set, write down the complements of the following sets: (x) $\{ x : x \ge 7 \}$

If $A = \{3, 6, 9, 12, 15, 18, 21\}$, $B = \{ 4, 8, 12, 16, 20 \}$, $C = \{ 2, 4, 6, 8, 10, 12, 14, 16 \}$, $D = \{5, 10, 15, 20 \}$; find (vii) $B – C$

Which of the following sets are finite or infinite (i) The set of months of a year

From the sets given below, select equal sets : $A = \{ 2, 4, 8, 12\}$, $B = \{ 1, 2, 3, 4\}$, $C = \{ 4, 8, 12, 14\}$, $D = \{ 3, 1, 4, 2\}$ $E = \{–1, 1\}$, $F = \{ 0, a\}$, $G = \{1, –1\}$, $H = \{ 0, 1\}$

Let $U = \{ 1, 2, 3, 4, 5, 6, 7, 8, 9 \}$, $A = \{ 1, 2, 3, 4\}$, $B = \{ 2, 4, 6, 8 \}$ and $C = \{ 3, 4, 5, 6 \}$. Find (i) A′

Draw appropriate Venn diagram for each of the following : (i) $(A \cup B)′$

List all the elements of the following sets : (v) $E = \{x : x$ is a month of a year not having 31 days\}

State whether each of the following statement is true or false. Justify your answer. (iv) \{ 2, 6, 10 \} and \{ 3, 7, 11\} are disjoint sets.

In each of the following, determine whether the statement is true or false. If it is true, prove it. If it is false, give an example. (i) If $x \in A$ and $A \in B$, then $x \in B$

State whether each of the following set is finite or infinite: (ii) The set of letters in the English alphabet

If $A = \{3, 6, 9, 12, 15, 18, 21\}$, $B = \{ 4, 8, 12, 16, 20 \}$, $C = \{ 2, 4, 6, 8, 10, 12, 14, 16 \}$, $D = \{5, 10, 15, 20 \}$; find (xii) $D – C$

State whether each of the following set is finite or infinite: (i) The set of lines which are parallel to the x-axis

If $A = \{3, 6, 9, 12, 15, 18, 21\}$, $B = \{ 4, 8, 12, 16, 20 \}$, $C = \{ 2, 4, 6, 8, 10, 12, 14, 16 \}$, $D = \{5, 10, 15, 20 \}$; find (viii) $B – D$

Which of the following sets are finite or infinite (ii) \{1, 2, 3, . . .\}