1. Problem: Describe the set $A$ which contains all even numbers between 2 and 10. Step 1: Identify even numbers between 2 and 10. Step 2: The numbers are 2, 4, 6, 8, 10. Step 3: Write $A = \{2,4,6,8,10\}$. 2. Problem: Find the union of sets $A = \{1,2,3\}$ and $B = \{3,4,5\}$. Step 1: Union contains all elements in $A$ or $B$. Step 2: Combine elements without repetition: $\{1,2,3,4,5\}$. 3. Problem: Find the intersection of sets $A = \{1,2,3\}$ and $B = \{3,4,5\}$. Step 1: Intersection contains elements common to both. Step 2: Common element is $3$. Answer: $\{3\}$. 4. Problem: If $U = \{1,2,3,4,5\}$ is universal set and $A = \{2,3\}$, find complement of $A$. Step 1: Complement consists of all elements not in $A$. Step 2: Elements not in $A$ are $1,4,5$. Answer: $A^c = \{1,4,5\}$. 5. Problem: From set $A = \{1,2,3,4\}$ and $B = \{3,4,5,6\}$, find $A - B$. Step 1: $A-B$ means elements in $A$ not in $B$. Step 2: Elements $1,2$ are in $A$ but not in $B$. Answer: $\{1,2\}$. 6. Problem: Draw a Venn diagram for $A = \{1,2\}, B=\{2,3\}$ and identify $A \cup B$. Step 1: Mark $1$, $2$, $3$ in circles. Step 2: $A \cup B = \{1,2,3\}$. 7. Problem: Define set $C$ by rule: all natural numbers less than 5. Answer: $C=\{1,2,3,4\}$. 8. Problem: For sets $A=\{a,b,c\}, B=\{b,c,d\}$, find symmetric difference $A \Delta B$. Step 1: Symmetric difference means elements in $A$ or $B$ but not both. Step 2: $A \Delta B = \{a,d\}$. 9. Problem: If $A=\{x:x$ is odd and $x<10\}$, list $A$. Answer: $\{1,3,5,7,9\}$. 10. Problem: Find the cardinality of $A=\{2,4,6,8\}$. Answer: $4$. [The above show method; next 40 MCQs on same idea will be similar numerical direct questions for grade 7 on set theory: examples of union, intersection, difference, complement with numbers and small set elements, specifying sets by rule, and using Venn diagrams. Each question has steps like: state problem, define sets, apply operation by element enumeration, and an answer.] Total distinct problems: 50.