What the board asks

We went through the ISC board papers, question by question, and matched each question to a topic. Here is what was asked, how often, and what was never asked.

Computer Science: 180 topics in the 2027 syllabus, across 10 units. The board has asked 117 of them at least once. 63 were never asked in the papers we checked.

Pick a unit

CS1 Boolean Algebra

This unit carries about 14 marks in the paper. We split it into 27 topics: each is one thing an examiner can ask, and you can practise it on paper in 5 to 25 minutes. The board has asked 23 of them. 4 were never asked. The top 5 topics make 44% of all the times this unit was asked. Last asked: 2026.

The syllabus says: Karnaugh maps up to four variables.

23asked by the board at least once

4in the syllabus, never asked

100times a topic of this unit was asked

3.8hours for one attempt at every topic

What the papers ask most

  • Principle of duality: state it and write the dual9 times, last 2026
  • Complement of an expression using De Morgan's theorem9 times, last 2026
  • Word problem to truth table and SOP or POS9 times, last 2026
  • K-map reduction of a four-variable POS expression9 times, last 2026
  • K-map reduction of a four-variable SOP expression8 times, last 2025 improvement
  • Truth table to classify tautology, contradiction or contingency6 times, last 2026
  • Convert between cardinal and canonical forms6 times, last 2025 improvement
  • State and identify Boolean postulates and theorems5 times, last 2026
  • Logic gate diagram for a reduced SOP or POS5 times, last 2026
  • Converse, inverse and contrapositive of an implication in symbols5 times, last 2025 improvement

In the syllabus, never asked (4)

They can still come, because they are in the syllabus. Give each one clean attempt. Your plan has two practice questions for each.

  • Write a word statement as a wffSum
  • Truth table of a compound proposition (all connectives)Sum
  • Truth tables for half adder, full adder, majority circuitSum
  • K-map reduction of a two- or three-variable expressionSum

All the topics in Computer Science: Boolean Algebra →

The 10 topics Computer Science papers ask most

Counted on the board papers from 2018 to the 2027 specimen paper, which every unit has been checked against.

  1. 1.Principle of duality: state it and write the dualCS1 Boolean Algebra · asked 8 times since 2018
  2. 2.Complement of an expression using De Morgan's theoremCS1 Boolean Algebra · asked 8 times since 2018
  3. 3.Word problem to truth table and SOP or POSCS1 Boolean Algebra · asked 8 times since 2018
  4. 4.K-map reduction of a four-variable POS expressionCS1 Boolean Algebra · asked 8 times since 2018
  5. 5.Pre-order, in-order and post-order traversalCS9 Data Structures · asked 8 times since 2018
  6. 6.K-map reduction of a four-variable SOP expressionCS1 Boolean Algebra · asked 7 times since 2018
  7. 7.Read a tree: leaves, internal nodes, parent, siblings, degreeCS9 Data Structures · asked 7 times since 2018
  8. 8.Truth table to classify tautology, contradiction or contingencyCS1 Boolean Algebra · asked 6 times since 2018
  9. 9.Convert between cardinal and canonical formsCS1 Boolean Algebra · asked 6 times since 2018
  10. 10.Address of an element, row major and column majorCS6 Arrays and Strings · asked 6 times since 2018

See when each unit comes in your plan