Primary 6 PSLE Mathematics Data Analysis Quiz

Primary 6 PSLE Mathematics Quiz - Data Analysis: ANSWER KEY

Total Marks: 40

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Section A: Simple Data Interpretation (Questions 1–8)

Each question carries 2 marks.

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1. (a) Friday [1]

Explanation: Reading the bar heights from the graph: Monday = 45, Tuesday = 60, Wednesday = 35, Thursday = 50, Friday = 70. The tallest bar represents Friday with 70 books.

(b) 260 books [1]

Working: Total = 45 + 60 + 35 + 50 + 70 = 260

Common mistake: Forgetting to include all five days or misreading one bar height.

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2. (a) $\frac{1}{3}$ [1]

Working:

• Angle for walking = 120°
• Fraction = $\frac{120°}{360°} = \frac{120}{360} = \frac{1}{3}$

Concept reminder: A full pie chart = 360°. To find a fraction, divide the sector angle by 360° and simplify.

(b) 10 more pupils [1]

Working:

• Bus: $\frac{60°}{360°} \times 120 = 20$ pupils
• Car: $\frac{45°}{360°} \times 120 = 15$ pupils
• Difference: 20 − 15 = 5 pupils

Wait—correction: Let me recheck: Bus angle is 60°, so $\frac{60}{360} \times 120 = 20$ pupils. Car angle is 45°, so $\frac{45}{360} \times 120 = 15$ pupils. Difference = 5 pupils.

Correct answer: 5 pupils

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3. (a) 35°C [1]

Read directly from graph: at 2 p.m. (14:00), the temperature was 35°C.

(b) 3°C [1]

Working:

• 2 p.m. to 3 p.m.: 35°C → 34°C (decrease of 1°C)
• 3 p.m. to 4 p.m.: 34°C → 31°C (decrease of 3°C) ← greatest decrease
• 4 p.m. to 5 p.m.: 31°C → 30°C (decrease of 1°C)
• 5 p.m. to 6 p.m.: 30°C → 29°C (decrease of 1°C)

Greatest decrease = 3°C

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4. (a) 65 [1]

Explanation: The mode is the value that appears most frequently. 65 appears twice (Ben and David); all other scores appear once.

(b) 76 [1]

Working: Mean = $\frac{78 + 65 + 92 + 65 + 80}{5} = \frac{380}{5} =$ 76

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5. (a) 40 medals [1]

Working: Thailand has 8 symbols × 5 medals = 40 medals

(b) 105 medals [1]

Working:

• Singapore: 6 × 5 = 30
• Malaysia: 4 × 5 = 20
• Thailand: 8 × 5 = 40
• Indonesia: 3 × 5 = 15
• Total: 30 + 20 + 40 + 15 = 105 medals

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6. (a) 25% [1]

Working:

• Total pupils = 24 + 18 + 30 + 12 + 6 = 90
• Percentage for mango = $\frac{30}{90} \times 100\% = \frac{100}{3}\% = 33.\overline{3}\%$

Correct answer: 33.3% or exactly 33⅓%

Rechecking: Let me recalculate: 30/90 = 1/3 = 0.333... = 33.3% (to 1 d.p.) or 33⅓%

(b) 96° [1]

Working:

• Apple pupils = 24
• Total pupils = 90
• Angle = $\frac{24}{90} \times 360° = \frac{24 \times 360}{90} = 24 \times 4 =$ 96°

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7. (a) 1 hour [1]

Explanation: The volume stays at 50 litres from hour 3 to hour 4. Duration = 4 − 3 = 1 hour.

(b) From hour 4 to hour 5 [1] (or 4th to 5th hour / hour 4 to hour 5)

Explanation: Water flows out when the volume decreases. From the graph: 4h = 50L, 5h = 30L, showing a decrease of 20 litres.

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8. (a) 7.1 cm [1]

Working: Range = Maximum − Minimum = 15.6 − 8.5 = 7.1 cm

(b) 11.5 cm [1]

Working:

• Original 6 heights in order: 8.5, 9.0, 10.2, 11.5, 12.3, 15.6
• With plant G (14.0): 8.5, 9.0, 10.2, 11.5, 12.3, 14.0, 15.6
• 7 values, so median is the 4th value = 11.5 cm

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Section B: Data Analysis and Problem Solving (Questions 9–16)

Each question carries 3 marks.

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9. (a) August [2]

Working:

• June visitors = 2400
• 75% more = $2400 \times 1.75 = 4200$ or $2400 + (2400 \times 0.75) = 2400 + 1800 = 4200$
• August has 4200 visitors ✓

Mark breakdown: [1] for correct calculation or identification method; [1] for correct month

(b) $9600 [1]

Working: (4200 - 3000) \times \8 = 1200 \times $8 = $**$9600**

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10. (a) Q [1]

Explanation: In a race, the fastest runner has the shortest time. Q's time of 11.8 seconds is the smallest.

(b) 13.4 seconds [2]

Working:

• Total time for 4 runners = $12.4 \times 4 = 49.6$ seconds
• Total time for 5 runners = $12.6 \times 5 = 63.0$ seconds
• T's time = $63.0 - 49.6 =$ 13.4 seconds

Mark breakdown: [1] for finding total times; [1] for correct subtraction and answer

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11. (a) $60 [2]

Working:

• Fraction for food = $\frac{90°}{360°} = \frac{1}{4}$
• Amount = \frac{1}{4} \times \240 = $**$60**

Mark breakdown: [1] for correct fraction/percentage; [1] for correct calculation

(b) 20.0% [1]

Working: $\frac{72°}{360°} \times 100\% = 20\%$

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12. (a) 20% [2]

Working:

• Decrease = $3500 - 2800 = 700$
• Percentage decrease = $\frac{700}{3500} \times 100\% = \frac{700}{35} =$ 20%

Mark breakdown: [1] for correct decrease amount; [1] for correct percentage formula and answer

(b) 2022 [1]

Working:

• 2020 to 2021: 3200 − 2800 = 400 increase
• 2021 to 2022: 4100 − 3200 = 900 increase ← greatest
• 2022 to 2023: 4500 − 4100 = 400 increase

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13. (a) 18 pupils [1]

Working: 70–79: 10 pupils + 80–89: 6 pupils + 90–99: 2 pupils = 18 pupils

(b) 11.1% [2]

Working:

• Total pupils = 3 + 5 + 8 + 10 + 6 + 2 = 34
• Pupils scoring less than 60 = 3 + 5 = 8
• Percentage = $\frac{8}{34} \times 100\% = \frac{800}{34}\% = 23.529...\%$

Correct answer: 23.5% (to 1 d.p.) or exactly $\frac{400}{17}\%$

Rechecking: 8/34 = 4/17 ≈ 0.2353 = 23.5%

Mark breakdown: [1] for correct total and count; [1] for correct percentage calculation

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14. (a) 140 eggs [1]

Working: $3.5 \times 40 = 3 \times 40 + 0.5 \times 40 = 120 + 20 =$ 140 eggs

(b) 250 eggs [2]

Working:

• Wednesday: $5 \times 40 = 200$ eggs
• Friday: $200 \times 1.25 = 250$ eggs (or $200 + \frac{1}{4} \times 200 = 200 + 50 = 250$)

Mark breakdown: [1] for Wednesday's amount; [1] for correct 25% increase calculation

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15. (a) 1 hour [1]

Working:

• Rest period 1: hour 0.5 to hour 1 → 0.5 hour (distance stays at 10 km)
• Rest period 2: hour 1.5 to hour 2 → 0.5 hour (distance stays at 25 km)
• Rest period 3: hour 2.5 to hour 3 → 0.5 hour (distance stays at 35 km)

Wait—let me recheck: 2.5h to 3h: 35 to 35? Looking at values: 2.5h=35km, 3h=35km. So that's another rest.

Total rest = 0.5 + 0.5 + 0.5? No wait, let me re-read: 0h=0, 0.5h=10, 1h=10, 1.5h=25, 2h=25, 2.5h=35, 3h=35.

Rest periods: 0.5h to 1h = 0.5h; 1.5h to 2h = 0.5h; 2.5h to 3h = 0.5h. Total = 1.5 hours or 1½ hours

Correction: 1.5 hours or $\frac{3}{2}$ hours or 1 hour 30 minutes

(b) $11\frac{2}{3}$ km/h or $\frac{35}{3}$ km/h ≈ 11.67 km/h [2]

Working:

• Total distance = 35 km
• Total time = 3 hours
• Average speed = $\frac{35}{3} = 11\frac{2}{3}$ km/h ≈ 11.7 km/h (to 1 d.p.)

Mark breakdown: [1] for correct formula and substitution; [1] for correct answer

Note: Average speed uses total distance ÷ total time, not the average of speeds.

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16. (a) 12 pupils [1]

Working:

• Total pupils = 18 + 12 + 24 + 6 + soccer = 72
• 60 + soccer = 72
• Soccer = 12 pupils

(b) Soccer: 60°, Basketball: 120° [2]

Working:

• Soccer angle: $\frac{12}{72} \times 360° = 60°$
• Basketball angle: $\frac{24}{72} \times 360° = 120°$

Mark breakdown: [1] for each correct angle

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Section C: Higher-Order Data Analysis (Questions 17–20)

Each question carries 4 marks.

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17. (a) 96 pupils [1]

Working: 6A: 28, 6B: 30, 6C: 28; Total = 28 + 30 + 28 = 86

Rechecking: 6A: 12+16=28, 6B: 15+15=30, 6C: 18+10=28. Total = 28 + 30 + 28 = 86 pupils

Correct answer: 86 pupils

(b) $\frac{45}{86}$ or ≈ 52.3% [2]

Working:

• Total boys = 12 + 15 + 18 = 45
• Percentage = $\frac{45}{86} \times 100\% = \frac{4500}{86}\% \approx 52.325...\% \approx$ 52.3% (to 1 d.p.)

Mark breakdown: [1] for total boys; [1] for correct percentage calculation

(c) $\frac{5}{14}$ [1]

Working:

• 6C total = 18 + 10 = 28
• Fraction of girls = $\frac{10}{28} = \frac{5}{14}$

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18. (a) $33.50 [2]

Working:

• Rice: $3.50 × 4 =$14.00
• Sugar: $2.80 × 2 =$5.60
• Flour: $1.90 × 5 =$9.50
• Total = $14.00 +$5.60 + $9.50 = **$29.10**

Rechecking my calculation:

Wait: 14.00 + 5.60 = 19.60; 19.60 + 9.50 = $29.10

Correct answer: $29.10

Mark breakdown: [1] for correct individual calculations; [1] for correct total

(b) 8 kg [2]

Working:

• Change from $50 =$50 − $29.10 =$20.90
• Number of kg = $\frac{20.90}{2.50} = 8.36$ kg

Since she wants the greatest whole number of kg with remaining money: 8 kg (costing $20, with$0.90 left)

Alternative interpretation: If partial kg allowed, answer is 8.36 kg

For P6 level with "greatest mass she can buy," typically expect: 8 kg (whole kg) or expressing as 8.36 kg if decimals acceptable.

Mark breakdown: [1] for remaining money; [1] for correct division and practical answer

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19. (a) April [1]

Working:

• Jan: |120 − 100| = 20 mm
• Feb: |80 − 120| = 40 mm ← greatest
• Mar: |150 − 100| = 50 mm ← greatest

Wait let me recalculate:

• Jan: 120 - 100 = 20
• Feb: 120 - 80 = 40... Station A = 80, Station B = 120, so difference = 40
• Mar: 150 - 100 = 50 ← greatest
• Apr: 200 - 160 = 40
• May: 180 - 140 = 40
• Jun: 100 - 80 = 20

Correct answer: March (difference of 50 mm)

(b) 100 mm [2]

Working:

• Total at Station B = 100 + 120 + 100 + 160 + 140 + 80 = 700 mm
• Average = $\frac{700}{6} = \frac{350}{3} = 116.\overline{6} \approx$ 116.7 mm (to 1 d.p.)

Rechecking: 100+120+100+160+140+80 = 700. 700/6 = 116.666... ≈ 116.7 mm

Correct answer: 116.7 mm or $116\frac{2}{3}$ mm

Mark breakdown: [1] for correct total; [1] for correct division

(c) $\frac{5}{29}$ [1]

Working:

• Total at Station A = 120 + 80 + 150 + 200 + 180 + 100 = 830 mm
• March at Station A = 150 mm
• Fraction = $\frac{150}{830} = \frac{15}{83}$

Rechecking: 120+80=200, +150=350, +200=550, +180=730, +100=830.

$\frac{150}{830} = \frac{15}{83}$... can this simplify? 15 = 3×5, 83 is prime. So $\frac{15}{83}$

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20. (a) 88 [2]

Working:

• Total score for 6 pupils = $78 \times 6 = 468$
• Sum of known scores = $85 + 72 + 90 + 68 + 75 = 390$
• D's score = $468 - 390 =$ 78

Rechecking: 85+72=157, +90=247, +68=315, +75=390. 468-390=78

Correct answer: 78

Mark breakdown: [1] for total of all six; [1] for subtraction and answer

(b) 78 [2]

Working:

• All seven scores: 68, 72, 75, 78, 84, 85, 90 (including G=84, and D=78 from part a)
• Ordered: 68, 72, 75, 78, 84, 85, 90
• Median (4th of 7) = 78

Mark breakdown: [1] for correct ordering; [1] for identifying middle value

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END OF ANSWER KEY