Worksheets › Class 7 › Decomposition: Clues, Ratios and Schedules
Class 7 · Computational Thinking and AI worksheetDecomposition: Clues, Ratios and Schedules
CBSE Computational Thinking and AI. Layered number clues, ratio and percentage steps, jobs that wait for each other, counting with OR, elimination puzzles. Every sheet has 20 questions in three sections and an answer key, and the questions change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
Multiples of 3 or 5 (or both) from 1 to 30 number:
- 10
- 15
- 16
- 14
Answer
(d) 14
- 2.
I am a 3-digit number. The sum of my digits is 13. I am odd. My hundreds digit is 7. All my digits are different. I am a multiple of 5. Who am I?
- 517
- 706
- 715
- 724
Answer
(c) 715
check the clues one by one; only this number fits all of them
- 3.
Five jobs: A takes 3 min; B takes 6 min and starts only after A is done; C takes 3 min and starts only after A is done; D takes 9 min and starts only after A and B are done; E takes 2 min and starts only after C and D are done. Jobs can run at the same time when their rules allow. What is the shortest time, in minutes, to finish all five?
- 23 min
- 20 min
- 21 min
- 9 min
Answer
(b) 20 min
finish times: A 3, B 9, C 6, D 18, E 20
Section B · short answer
- 4.
How many numbers from 1 to 60 are multiples of 4 or 6? Show the working.
Answer
15 + 10 − 5 = 20 (multiples of 12 are counted twice).
- 5.
I am a 4-digit number. I am a multiple of 5. My thousands digit is 9. The sum of my digits is 28. I am between 9,897 and 9,965. Who am I?
Answer
9,955
check the clues one by one; only this number fits all of them
Section C · long answer
- 6.
Plan a sports day by decomposition: list four sub-problems, one dependency between them and how you would check the plan works.
Answer
Sub-problems: events list, timetable, equipment, volunteers. Dependency: the timetable can only be made after the events are chosen. Check: walk through the day’s timetable to see that every event has equipment and helpers.
Fresh sheets for your child
In the app, every Decomposition: Clues, Ratios and Schedules sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
Coming soon for Android and iPhone.