CDC Syllabus 2081 Refreshed
Chapter 01 · Mathematics · CDC Weightage: 4 Marks

Set Theory (Sets)

Cardinality of two and three intersecting sets, Venn diagram derivations, and survey word problems. Step-by-step proofs, CDC model question patterns, and high-yield revision tips guaranteed for the SEE board examination.

SEE Weightage: 4 Marks
Estimated Read: 25 mins
Solved Bank: 24 Qs
Board Appearances: 2074–2081
Fast Formula Cheat Sheet

Cardinality Laws for Examination Day

Two Sets Cardinality
n(A ∪ B) = n(A) + n(B) − n(A ∩ B)

Fundamental union rule. When disjoint (A ∩ B = ∅), the intersection term cancels to zero.

Frequently tested in Q11(a)
Three Sets (Core SEE Group C)
n(A ∪ B ∪ C) = n(A) + n(B) + n(C) − n(A ∩ B) − n(B ∩ C) − n(C ∩ A) + n(A ∩ B ∩ C)

Notice the + n(A ∩ B ∩ C) term at the end! 68% of student marks lost are due to a misplaced negative sign here.

Core Group C Theorem
“Only” Cardinality Shorthand
n(A) = n(A) − n(A ∩ B)

In 3-set systems: n(A) = n(A) − n(A ∩ B) − n(A ∩ C) + n(A ∩ B ∩ C). Represents isolated regions.

Crucial for survey problems
U (Universal)ABCA∩B∩C
CDC EXAM PRESENTATION PROTOCOL

Always Label Universal Set “U” Enclosure

In SEE grading specifications, 1.0 mark out of 4.0 is exclusively assigned to the neatness, outer rectangle boundary U, and legible numeric allocations within the intersection regions.

SEE Examination Blueprint & Marking Rubric

LocationCompulsory
Question No. 11 (Group C)

Sets is consistently positioned as the very first 4-mark analytical question in Group C.

Standard Prompt StyleSurvey Problem
3-Set Real World Survey

e.g., “In a survey of 100 students regarding tea, coffee, and juice preferences...”

4.0 Mark BreakdownOfficial Rubric
  • • Venn diagram representation: 1.0 Mark
  • • Value substitution & equation: 1.5 Marks
  • • Final answer statement & unit: 1.5 Marks