Cambridge A Level Information Technology (ICT): Modelling (9626) – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover topic 9, Modelling, of Cambridge International AS & A Level Information Technology (9626), following the syllabus for examination in 2025, 2026 and 2027 (version 3), section 9.1 Modelling and simulations. Topic 9 is an AS Level topic. Paper 1 (Theory) questions are based on sections 1–11 and Paper 2 (Practical) tasks on sections 8–11. Every question here can be answered on paper; the spreadsheet questions practise the thinking behind the practical skills.

Learn the content first in the Modelling study guide and the Modelling revision notes. Course hub: Cambridge A Level ICT. Checklist: 9626 checklist. Find your weak spots with a free 10-minute diagnostic.

The answers show one acceptable set of points with a [1] for each creditworthy point. They are indicative marking written for this practice set, not official mark schemes; other valid points would also earn credit.

Questions

1. Explain the difference between a computer model and a simulation. [2]

2. Explain the difference between what-if analysis and goal seek. [2]

3. A drama club uses this spreadsheet to plan a concert.

	A	B
1	Ticket price (£)	6.00
2	Cost per person (£)	1.50
3	Hall hire (£)	450
4	Tickets sold	160
5	Profit (£)

(a) Write a formula for cell B5. [2] (b) Calculate the profit shown in B5. [1] (c) Predict the profit if the ticket price is raised to £7.00 with sales unchanged. Explain your prediction. [2] (d) Describe how goal seek could find the number of tickets needed to break even, and state the value it returns. [4]

4. A town of 24,000 people is modelled as growing by 3% a year.

(a) Calculate the predicted population after 3 years, to the nearest whole number. [2] (b) A second scenario uses 4% a year. Calculate the population after 3 years, to the nearest whole number. [1] (c) State one reason why the 3% assumption may not hold. [1]

5. Describe three characteristics of modelling software. [3]

6. At a busy junction, one minute of green light lets 18 cars through. At peak time 540 cars an hour arrive on the main road.

(a) Calculate how many minutes of green light the main road needs each hour. [1] (b) Traffic is forecast to rise by 25%. Calculate the new number of minutes of green light needed each hour. [2] (c) Explain two reasons why engineers test new light timings in a computer model rather than on the real road. [4]

7. Explain why computer models are needed to study climate change. [4]

8. A regional airline plans to move its engine-failure and crosswind-landing practice from real aircraft to a flight simulator. Discuss the advantages and disadvantages of this plan. [6]

9. A city council wants to plan for a major river flood. Describe how a computer model could be used to create and run a simulation to help it plan. [5]

10. (a) Give two benefits to a learner of using a simulator when learning to drive a car. [2] (b) Explain why simulations are used in nuclear science research. [3]

11. For each of these uses of what-if analysis, identify one input the model would change and one output it would predict:

(a) queue management at a hospital reception [2] (b) construction of a footbridge [2]

12. A bakery models its weekly profit. Each loaf sells for £2.40 and costs £0.90 to make. Fixed costs are £630 a week and it sells 500 loaves a week.

(a) Calculate the weekly profit. [2] (b) The owner wants a weekly profit of £300 without changing sales. Describe how goal seek finds the price needed, and state the price. [4] (c) The owner thinks the higher price will cut sales by 10%. Use the model to calculate the new profit, and comment on the result. [2] (d) Evaluate how far the owner should rely on this spreadsheet model when deciding the price. [4]

Answers

1. A model is a representation of a real system using variables and rules (formulas) [1]; a simulation is the model being run, for example over time or under chosen conditions, to see how the system behaves [1]. [2] Examiner insight: Two separate points are needed: define each term, not just one of them.

2. What-if analysis changes input values to see the effect on the output [1]; goal seek sets a target value for the output and finds the input value needed to reach it [1]. [2] Examiner insight: “Changing data” alone describes what-if; say which way round goal seek works.

3. (a) =B4(B1-B2)-B3* (or equivalent): tickets × (price − cost) [1], minus hall hire [1]. (b) 160 × 4.50 − 450 = £270 [1] (c) Each ticket earns £1 more, so profit rises by 160 × 1 = £160 [1], to £430 [1]. (d) Set cell B5 [1]; to value 0 [1]; by changing cell B4 [1]; goal seek returns 100 tickets [1]. [9] Examiner insight: In (a), a formula with typed values such as 160*4.5-450 does not update when inputs change, so use cell references.

4. (a) 24000 × 1.03³ [1] = 26,225 [1] (b) 24000 × 1.04³ = 26,997 [1] (c) Any one: birth, death or migration rates may change; new housing or jobs may attract people; a major event may change growth [1]. [4] Examiner insight: Round to whole people only at the end; rounding each year changes the final figure.

5. Any three, each described: variables can be changed easily [1]; formulas/rules link the variables and recalculate automatically [1]; what-if and goal seek tools [1]; saved scenarios for comparison; time steps to show change over time; random values for chance events; results shown as graphs or charts. [3] Examiner insight: “Easy to use” is not a characteristic of modelling software; name a feature.

6. (a) 540 ÷ 18 = 30 minutes [1] (b) 540 × 1.25 = 675 cars [1]; 675 ÷ 18 = 37.5 minutes [1] (c) Any two explained: testing on the real road would cause congestion or accidents [1] – the model puts no drivers at risk [1]; many timings can be tried quickly [1] – far faster than a separate real trial for each option [1]; cheaper than changing real equipment repeatedly. [7] Examiner insight: For “explain”, each reason needs a point and a development, not a one-word list.

7. Any four: the real system cannot be experimented on [1]; changes happen over decades, which a model can calculate in minutes [1]; many scenarios (different emission levels) can be compared [1]; predictions can guide decisions before it is too late to act [1]; models can be tested against past climate data. [4] Examiner insight: Points must be about climate change, not generic benefits of computers.

8. Advantages, any three: emergencies such as engine failure practised with no danger [1]; no fuel used or aircraft wear [1]; scenarios (bad weather, rare faults) repeated as often as needed [1]; trainee performance can be recorded and replayed. Disadvantages, any two: simulators are very expensive to buy and maintain [1]; pilots know they are not in real danger, so stress differs from a real emergency [1]. Conclusion, e.g. valuable for practice but real flying hours are still needed [1]. [6] Examiner insight: “Discuss” needs both sides and a conclusion; a list of advantages alone does not show discussion.

9. Data about the area is entered, such as land height, river levels and rainfall [1]; rules describe how water spreads [1]; the simulation is run for different scenarios, e.g. heavier rain or a failed flood barrier [1]; output shows which areas flood and when [1]; the council uses this to plan evacuation routes, shelters or where to place emergency resources [1]. [5] Examiner insight: Describe the stages (data, rules, run, output, use); listing benefits alone does not describe how the simulation is used.

10. (a) Any two: hazards practised without risk to the learner or others [1]; mistakes can be made safely and repeated [1]; bad weather or night driving practised at any time. (b) Experiments with radioactive material are dangerous [1]; a simulation avoids exposure to radiation [1]; it can test conditions that would be impossible or too costly to create for real [1]. [5] Examiner insight: In (b), “it is safer” earns little unless you say what the danger is.

11. (a) Input: number of reception staff or patient arrival rate [1]; output: waiting time or queue length [1]. (b) Input: materials, loads or dimensions [1]; output: whether the bridge is safe under load, or its cost [1]. [4] Examiner insight: Keep input and output distinct; “the queue” on its own is neither.

12. (a) 500 × (2.40 − 0.90) − 630 [1] = £120 [1] (b) Set the profit cell [1] to value 300 [1] by changing the price cell [1]; price = £2.76 [1]. (c) 450 × (2.76 − 0.90) − 630 = £207 [1]; profit rises from £120 but falls short of the £300 target, so the goal-seek price alone does not meet the target if sales drop [1]. (d) For: quick to test prices and sales levels with what-if analysis [1]; uses the bakery’s own cost figures [1]. Against: the 10% fall is only an estimate, and real demand may differ [1]. Judgement: useful for comparing options, but the owner should test the price and update the model with real sales [1]. [12] Examiner insight: In (c), use the price found in (b); a correct method using a wrong carried value still shows the right working.

Where marks are usually lost

• Writing formulas with typed numbers instead of cell references.
• Naming a formula cell as the “cell to change” in goal seek.
• Not rounding to whole tickets, people or staff when the context needs it.
• Rounding part-way through a growth calculation.
• Describing the benefits of a simulation without linking them to the named use (pilots, floods, driving, nuclear research).
• Giving one side only for “discuss” or “evaluate”, or leaving out a conclusion.
• Writing “cheaper” or “safer” without saying than what.
• Confusing a model’s input with its output.

Next steps

• Modelling revision notes
• Modelling study guide
• Monitoring and Control practice questions
• Cambridge A Level ICT course hub
• 9626 printable checklist
• All free 10-minute diagnostics
• Book a free trial class

Official syllabus

Cambridge International AS & A Level Information Technology 9626, syllabus for examination in 2025, 2026 and 2027, version 3, Cambridge University Press & Assessment. Topic 9: Modelling (9.1 Modelling and simulations).