📑 Topics on this page (Jump to Topic):
📌 1. Main Diagram Types
| Relation | Diagram | Example |
|---|---|---|
| One inside another | Two circles, one inside | Rose, Flower |
| Three nested | Three nested circles | Delhi, India, Asia |
| Partial overlap | Two intersecting circles | Doctors, Women |
| Disjoint | Separate circles | Dogs, Cats |
| Two disjoint inside a larger | Two separate circles in a bigger one | Men, Women, Humans |
| Two overlap, third separate | Two intersecting + one apart | Teachers, Singers, Tables |
| All three overlap | Three intersecting circles | Players, Students, Girls |
⚠️ Exam Traps:
- 'Men' and 'Fathers': all fathers are men — one inside the other, not overlapping.
- 'Indians' and 'Doctors' overlap partially — non-Indian doctors and non-doctor Indians both exist.
📌 2. Region-based Questions
- 'Only A' = part of A not in any other shape.
- 'A and B but not C' = A∩B minus the C part.
- For two sets: n(A∪B) = n(A) + n(B) − n(A∩B).
💡 Memory Tip: Find the largest class first, then see whether others lie inside or outside it.
📌 3. Practice MCQs
📝 Practice MCQs (prepared by SF Prep — not PYQs)
Q1. Which diagram best shows 'Rose, Flower, Plant'? Practice
Correct answer: (B)
All roses are flowers and flowers belong to plants ⇒ nested circles.
All roses are flowers and flowers belong to plants ⇒ nested circles.
Q2. Which diagram represents 'Men, Women, Humans'? Practice
Correct answer: (C)
Men and women are both humans but separate from each other.
Men and women are both humans but separate from each other.
Q3. What is the relation between 'Doctors' and 'Women'? Practice
Correct answer: (D)
Some women are doctors and some doctors are men.
Some women are doctors and some doctors are men.
Q4. Correct diagram for 'Dog, Cat, Animal'? Practice
Correct answer: (A)
Dogs and cats are separate but both are animals.
Dogs and cats are separate but both are animals.
Q5. Correct diagram for 'Teachers, Singers, Tables'? Practice
Correct answer: (B)
Some teachers may be singers; tables are separate from both.
Some teachers may be singers; tables are separate from both.
Q6. Correct diagram for 'Players, Students, Girls'? Practice
Correct answer: (C)
A girl can be both student and player; all three partially overlap.
A girl can be both student and player; all three partially overlap.
Q7. Correct diagram for 'Delhi, India, Asia'? Practice
Correct answer: (D)
Delhi ⊂ India ⊂ Asia.
Delhi ⊂ India ⊂ Asia.
Q8. Correct diagram for 'Fathers, Men, Doctors'? Practice
Correct answer: (A)
All fathers are men; doctors include some fathers, some men and some women.
All fathers are men; doctors include some fathers, some men and some women.
Q9. In a class, 40 study Hindi and 30 study English; 10 study both. How many study at least one language? Practice
Correct answer: (B)
40 + 30 − 10 = 60.
40 + 30 − 10 = 60.
Q10. Among 50 people, 30 drink tea and 25 drink coffee; everyone drinks at least one. How many drink both? Practice
Correct answer: (C)
30 + 25 − 50 = 5.
30 + 25 − 50 = 5.
Q11. Correct diagram for 'Sun, Planets, Earth'? Practice
Correct answer: (D)
Earth is a planet; the Sun is a star, not a planet.
Earth is a planet; the Sun is a star, not a planet.
Q12. 'Nurses, Hospitals, Patients' — which is correct for classes? Practice
Correct answer: (A)
A hospital is a place, not a person ⇒ separate; a nurse can also be a patient.
A hospital is a place, not a person ⇒ separate; a nurse can also be a patient.
Q13. Of 100 students, 60 play cricket, 50 play football and 20 play both. How many play neither? Practice
Correct answer: (B)
At least one = 60 + 50 − 20 = 90; neither = 10.
At least one = 60 + 50 − 20 = 90; neither = 10.
Q14. Correct diagram for 'Squares, Rectangles, Quadrilaterals'? Practice
Correct answer: (C)
Every square is a rectangle, every rectangle a quadrilateral ⇒ nested.
Every square is a rectangle, every rectangle a quadrilateral ⇒ nested.
Q15. Correct diagram for 'Elephants, Lions, Herbivores'? Practice
Correct answer: (D)
Elephants are herbivores; lions are carnivores ⇒ separate.
Elephants are herbivores; lions are carnivores ⇒ separate.
Q16. A = 25, B = 20 and A∪B = 35. A∩B = ? Practice
Correct answer: (A)
25 + 20 − 35 = 10.
25 + 20 − 35 = 10.
Q17. Correct diagram for 'Parents, Fathers, Mothers'? Practice
Correct answer: (B)
Fathers and mothers are both parents but separate from each other.
Fathers and mothers are both parents but separate from each other.
Q18. Correct diagram for 'Metals, Iron, Oxygen'? Practice
Correct answer: (C)
Iron is a metal; oxygen is a non-metal ⇒ separate.
Iron is a metal; oxygen is a non-metal ⇒ separate.
Q19. In a survey 70% read paper A, 50% read paper B and 10% read neither. What % read both? Practice
Correct answer: (D)
At least one = 90%; 70 + 50 − 90 = 30%.
At least one = 90%; 70 + 50 − 90 = 30%.
Q20. Correct diagram for 'Indians, Doctors, Women'? Practice
Correct answer: (A)
An Indian woman can be a doctor; all three overlap partially.
An Indian woman can be a doctor; all three overlap partially.