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

CS7 Recursion

This unit carries about 6 marks in the paper. We split it into 15 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 10 of them. 5 were never asked. The top 5 topics make 79% of all the times this unit was asked. Last asked: 2026.

10asked by the board at least once

5in the syllabus, never asked

24times a topic of this unit was asked

3.9hours for one attempt at every topic

What the papers ask most

  • State what a recursive method does apart from recursion5 times, last 2026
  • Design a class with a recursive digit method5 times, last 2026
  • Output of a recursive method on an integer (dry run)5 times, last 2025
  • Output of a recursive base conversion method (dry run)2 times, last 2026
  • Output of a recursive method on an array (dry run)2 times, last 2025 improvement
  • Differences between iteration and recursiononce, last 2026
  • Recursion and the call stack: LIFO, missing base caseonce, last 2024
  • Design a class that converts number bases recursivelyonce, last 2024
  • Design a class with recursive binary search on an arrayonce, last 2020
  • Design a class with a recursive factor or GCD methodonce, last 2018

In the syllabus, never asked (5)

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

  • Define recursion, base case and recursive caseStatement
  • Write the recursive equation for a functionSum
  • Write a short recursive method from its definitionProgram
  • Tower of Hanoi: recursive method and list of movesDry run / output
  • Design a class with a recursive string methodProgram

All the topics in Computer Science: Recursion →

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