AQA GCSE Mathematics Paper 1 (Higher), June 2025: Question 22
3 marks · Medium difficulty · Multi-step Problem
Find the coordinates of point F on the line segment EG connecting E(-18, 9) and G(6, 3) such that EF is one third of EG.
Practise this questionQuestion
Question text
22 Here is a sketch of straight line EG.
F is a point on EG such that EF = EG
Work out the coordinates of F.
[3 marks]
Answer ( , )
Mark scheme
Show the mark scheme
Q Answer Mark Comments
Correct method for finding the eg 6 – (– 18) or 24
difference between the x or y
or
coordinates for the points E and G
(positive or negative differences) M1 3 – 9 or –6
implied by gradient = –
Correct method for finding the −18 − 6
difference between the x or y eg or –8 or –16
coordinates for the points E and F
or the points F and G M1dep or
(positive or negative differences) 9 – 3
or 2 or 4
(–10, 7) A1 SC1 (–2, 5) or (–12, 7.5) oe
Additional Guidance
SC1 (–2, 5) is for EF = EG
SC1 (–12, 7.5) is for EF = FG
Working may be seen on the diagram
(–10, …) or (…, 7) M1M1
How to answer it
Dividing a Line Segment in a Given Fraction
What this question tests
- Finding horizontal ( x ) and vertical ( y ) displacements between two coordinate points.
- Dealing carefully with directed negative numbers (e.g. subtracting a negative).
- Applying fractional scaling to vector translations along a line segment.
- Adding fractional displacements to the starting point to determine new coordinates.
Question 22 Walkthrough
Points E(−18, 9) and G(6, 3) where EF = ⅓ EG [3 marks]
📐 Step-by-Step Calculation
Find the full shift from the starting point E(−18, 9) to the end point G(6, 3) :
- Change in x = 6 − (−18) = 6 + 18 = 24
- Change in y = 3 − 9 = −6
Since point F lies one-third of the way from E towards G:
- x-step = ⅓ × 24 = 8
- y-step = ⅓ × (−6) = −2
Start at E(−18, 9) and add each step:
- x-coordinate of F = −18 + 8 = −10
- y-coordinate of F = 9 + (−2) = 7
✅ Final Answer
(−10, 7)
Partial credit: Getting one coordinate correct, e.g. (−10, ...) or (..., 7) , earns M1M1.
💡 Key Knowledge
- Vector Form: Position vector of F is F = E + ⅓(G − E) .
- Direction Matters: Movement is from E towards G. Since y drops from 9 to 3, the vertical step must be subtracted (or added as a negative).
🧠 Exam Technique & Examiner Tips
- Check by inspection on the sketch: Point E has x = −18 and G has x = 6. Point F must lie between them, closer to E. A value of x = −10 and y = 7 fits visually.
- Label your diagram: Drawing a horizontal-vertical right-angled triangle between E and G makes the differences of 24 and 6 immediately clear.
❌ Common Errors & Mark Scheme Traps
- Measuring from the wrong end: Calculating ⅓ from G instead of E gives (−2, 5) . This earns only SC1 (Special Case 1 mark).
- Ratio misinterpretation: Treating EF = ⅓ EG as a ratio of 1 : 3 instead of a fraction of the whole gives a factor of ¼, leading to (−12, 7.5) . This also only scores SC1.
- Sign slip: Calculating 6 − 18 = −12 instead of 6 − (−18) = +24. Always use brackets when subtracting negatives!
Topics
Algebra · Geometry and measures · 3.2.2 Graphs · 3.4.1 Properties and constructions
Question and mark scheme from the AQA GCSE Mathematics examination, Paper 1 (Higher), June 2025. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.