The answer
(a) the points are only the end-of-month values, so a mid-June reading is not given
(b) the cost between recorded months could be higher than any plotted point
(c)(i) the vertical axis does not start at 0
(ii) it exaggerates the differences between the monthly costs
O-Level E-Math 2025 Paper 1 Question 11 · Verified worked solution by the Genius Plus Academy teaching team
What this question tests
This is Question 11 of the O-Level E-Math 2025 Paper 1. It tests interpreting statistical graphs, in the Data handling area. It is worth 4 marks: 1 + 1 + 1 + 1. It is a worded / diagram-based question, so open your Ten-Year Series (TYS) or the official paper at this question, then follow our full worked solution below.
(a) Alex only records the cost at the end of each month, so the plotted points are end-of-month values. The line joining them is just a guide, it does not give the actual price in the middle of June, so reading off $3.32 for mid-June is not reliable.
(b) The graph only shows the cost at twelve specific moments (each month-end). The price could have risen above every plotted value at some time between two readings, so the true highest cost per litre is not necessarily on the graph.
(c)(i) The vertical (cost) axis does not start at 0, it starts at 2.60.
(ii) Because the axis is "cut", the bars/peaks look much taller relative to one another than they really are, so a reader sees the changes in fuel price as far bigger than the small actual differences. This exaggerates the variation.
Answer: (a) the points are only the end-of-month values, so a mid-June reading is not given
(b) the cost between recorded months could be higher than any plotted point
(c)(i) the vertical axis does not start at 0
(ii) it exaggerates the differences between the monthly costs
Same structure, different numbers
Swap the constants, dress a quadratic as a length, hide a derivative inside an integral, and a student sees a brand new problem. The structure underneath is the same, and so is the method. Once a student can name the structure, a whole row of questions that look different start to open the same way.
That is where marks really leak: in choosing the method, not in the algebra that follows. We call it Lock and Key, name the lock, then the key follows.
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Genius Plus Academy · O-Level & IP Mathematics
Our O-Level E-Math tuition trains the same recognise-the-structure method these worked solutions show, taught by a team that has marked these papers for years. It runs within our weekly Secondary Math programme, Sec 1 to 4 and IP.
It is a interpreting statistical graphs question from Data handling, worth 4 marks: 1 + 1 + 1 + 1.
Yes. IP (Integrated Programme) schools teach the same O-Level Mathematics content; they just sequence it differently and set their own internal exams, so these worked solutions apply to IP students too.
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