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GCSE November 2023 Edexcel Foundation Paper 3 (Calculator)
Legend
- ๐ก Understanding: The reasoning behind the question.
- โ Working: Mathematical steps and calculation.
- ๐ Interpretation: What the results mean.
- ๐ฏ Final Answer: The required solution for full marks.
- ๐ข Calculator: Steps to type into your calculator.
Table of Contents
- Question 1 (Percentages & Decimals)
- Question 2 (Rounding)
- Question 3 (Negative Numbers)
- Question 4 (Fractions of Shapes)
- Question 5 (Place Value)
- Question 6 (Pictograms)
- Question 7 (Arithmetic & Length)
- Question 8 (Number Sequences)
- Question 9 (Mass Conversion & Arithmetic)
- Question 10 (Polygons & Prisms)
- Question 11 (Ratio & Fractions)
- Question 12 (Time Calculations)
- Question 13 (Simplifying Algebra)
- Question 14 (Ordering Fractions/Decimals)
- Question 15 (Frequency Trees & Probability)
- Question 16 (Solving Equations)
- Question 17 (Currency Conversion)
- Question 18 (Area & Symmetry)
- Question 19 (Plans & Elevations)
- Question 20 (Standard Form)
- Question 21 (Relative Frequency)
- Question 22 (Mean & Median from Table)
- Question 23 (Inequalities)
- Question 24 (Lowest Common Multiple)
- Question 25 (Inverse Proportion)
- Question 26 (Speed, Distance, Time)
- Question 27 (Pressure, Force, Area)
- Question 28 (Equation of a Line)
- Question 29 (Circumference & Problem Solving)
Question 1 (1 mark)
Write 35% as a decimal.
Worked Solution
Step 1: Understanding Percentages
๐ก What does “percent” mean?
The word “percent” means “per 100” or “out of 100”. To convert a percentage to a decimal, we divide the number by 100.
Step 2: Converting to Decimal
โ Working:
\[ 35\% = \frac{35}{100} \]When we divide by 100, we move the decimal point two places to the left:
\[ 35.0 \div 100 = 0.35 \]๐ข Calculator Method:
Type 35 รท 100 =
๐ฏ Final Answer:
0.35
โ (B1)
Question 2 (1 mark)
Write 8061 correct to the nearest hundred.
Worked Solution
Step 1: Identifying the Columns
๐ก Strategy:
We need to round to the nearest hundred. Let’s look at the place value of the digits.
- 8 is in the Thousands column.
- 0 is in the Hundreds column (this is the digit we are rounding).
- 6 is in the Tens column (this is the “decider”).
- 1 is in the Units column.
Step 2: The Rounding Rule
โ Working:
Look at the digit to the right of the hundreds column (the tens digit): 6.
The rule is:
- If the decider is 5 or more, we round UP.
- If the decider is 4 or less, we round DOWN (keep the digit the same).
Since 6 is greater than 5, we round the hundreds digit (0) up to 1.
What this tells us:
The 0 becomes a 1, and everything after it becomes zero.
8061 is closer to 8100 than to 8000.
๐ฏ Final Answer:
8100
โ (B1)
Question 3 (1 mark)
Write down a number that is less than \( -5 \)
Worked Solution
Step 1: Understanding Negative Numbers
๐ก Thinking about the number line:
On a number line, “less than” means further to the left.
For negative numbers, a number is smaller (less) if the digit part looks bigger. For example, -10 is colder (less) than -5.
๐ฏ Final Answer:
Any number “more negative” than -5 is correct. Examples:
-6, -7, -8, -100, -5.1
โ (B1)
Question 4 (1 mark)
Here is a grid of squares.
What fraction of the grid is shaded?
Worked Solution
Step 1: Counting Squares
๐ก Strategy:
A fraction is written as: \[ \frac{\text{Number of shaded squares}}{\text{Total number of squares}} \]
โ Counting:
Number of columns = 7
Number of rows = 3
Total squares = \( 7 \times 3 = 21 \)
Number of shaded columns = 2
Shaded squares = \( 2 \times 3 = 6 \)
Step 2: Forming and Simplifying the Fraction
โ Working:
The fraction is:
\[ \frac{6}{21} \]We can simplify this by dividing both top and bottom by 3:
\[ \frac{6 \div 3}{21 \div 3} = \frac{2}{7} \]Observation: You can also see from the diagram that 2 out of the 7 full columns are shaded, which gives \( \frac{2}{7} \) directly.
๐ฏ Final Answer:
\( \frac{6}{21} \) or \( \frac{2}{7} \)
โ (B1)
Question 5 (1 mark)
Write down the value of the 9 in the number 27.963
Worked Solution
Step 1: Place Value Table
๐ก Why we do this:
We need to identify the position of the digit relative to the decimal point.
Step 2: State the Value
The 9 is in the first column after the decimal point.
This is the tenths column.
The value can be written as:
- 9 tenths
- \( \frac{9}{10} \)
- 0.9
Any of these forms are correct.
๐ฏ Final Answer:
9 tenths (or \( \frac{9}{10} \) or 0.9)
โ (B1)
Question 6 (4 marks)
The pictogram shows information about the number of chocolate cakes, vanilla cakes and lemon cakes sold by Year 7 at a school fair.
24 banana cakes were sold by Year 7.
(a) Use this information to complete the pictogram.
At the fair, Year 8 sold a total of 150 cakes.
(b) Which Year sold most cakes at the fair, Year 7 or Year 8?
You must show how you get your answer.
Worked Solution
Part (a): Completing the Pictogram
๐ก The Key: The key tells us that one full circle represents 12 cakes.
Target: We need to represent 24 banana cakes.
โ Calculation:
\[ 24 \div 12 = 2 \]We need to draw 2 full circles in the Banana row.
Part (b): Comparing Sales
๐ก Strategy: We know Year 8 sold 150 cakes. We need to calculate the total for Year 7 by interpreting the pictogram rows and adding them up.
โ Calculating Year 7 Total:
- Chocolate: 5 circles. \( 5 \times 12 = 60 \)
- Vanilla: 3 full circles + 1 quarter.
Quarter = \( 12 \div 4 = 3 \).
Total = \( (3 \times 12) + 3 = 36 + 3 = 39 \) - Lemon: 1 full circle + 1 half.
Half = \( 12 \div 2 = 6 \).
Total = \( 12 + 6 = 18 \) - Banana: 2 circles (from part a). \( 2 \times 12 = 24 \)
Total for Year 7:
\[ 60 + 39 + 18 + 24 = 141 \]๐ก Comparison:
Year 7 Total: 141
Year 8 Total: 150
150 is greater than 141.
๐ฏ Final Answer:
(a) Two full circles drawn in the Banana row.
(b) Year 8 sold the most cakes (150 vs 141).
โ (C1 for diagrams, M1 for totals, C1 for conclusion)
Question 7 (3 marks)
Miklos is swimming lengths of a swimming pool.
Each length of the pool is 25 m.
Miklos has swum 178 lengths of the pool.
He wants to swim a total distance of 8050 m.
Calculate how many more lengths Miklos needs to swim.
Worked Solution
Step 1: Understanding the Goal
๐ก Strategy: We have two options:
- Find the total number of lengths needed for 8050 m, then subtract the ones he has already done.
- Find the distance he has already swum, find the remaining distance, and convert that to lengths.
Let’s use Method 1 as it deals with smaller numbers sooner.
Step 2: Calculate Total Lengths Required
โ Working:
Total distance = 8050 m
Length of pool = 25 m
\[ \text{Total Lengths} = \frac{8050}{25} \]Using calculator: \( 8050 \div 25 = 322 \) lengths.
Step 3: Calculate Remaining Lengths
โ Working:
He has already done 178 lengths.
\[ \text{Lengths needed} = 322 – 178 \] \[ 322 – 178 = 144 \]Alternative Method
Distance swum = \( 178 \times 25 = 4450 \) m.
Distance remaining = \( 8050 – 4450 = 3600 \) m.
Lengths remaining = \( 3600 \div 25 = 144 \).
๐ฏ Final Answer:
144 lengths
โ (P1, P1, A1)
Question 8 (4 marks)
Here are the first four terms of a number sequence.
97 91 85 79
(a) Explain how to work out the next number of the sequence.
(b) Work out the difference between the 5th term and the 7th term of the sequence.
(c) Explain why 52 is not a number in this sequence.
Worked Solution
Part (a): Finding the Rule
โ Check the difference:
\( 91 – 97 = -6 \)
\( 85 – 91 = -6 \)
\( 79 – 85 = -6 \)
The sequence goes down by 6 each time.
Answer: Subtract 6 from the previous term.
โ (C1)
Part (b): 5th and 7th Terms
โ Extend the sequence:
4th term: 79
5th term: \( 79 – 6 = 73 \)
6th term: \( 73 – 6 = 67 \)
7th term: \( 67 – 6 = 61 \)
Find the difference:
\[ 73 – 61 = 12 \]Alternatively, the difference is two “steps” of 6, which is \( 2 \times 6 = 12 \).
Answer: 12
โ (M1, A1)
Part (c): Checking 52
๐ก Strategy: We need to check the properties of numbers in this sequence.
- The numbers are: 97, 91, 85, 79, 73, 67, 61, 55, 49…
Observation 1 (Parity):
All terms are odd numbers. (Odd – Even = Odd).
52 is an even number.
Answer: All numbers in the sequence are odd, but 52 is even.
โ (C1)
Question 9 (5 marks)
Mandy buys a 12 kilogram bag of dog food.
Mandyโs dog has 3 meals a day.
She gives her dog 105 grams of dog food for each of these meals.
How many complete weeks will the bag of dog food last?
You must show all your working.
Worked Solution
Step 1: Check Units
โ ๏ธ Critical Step: The bag is in kilograms (kg), but the meals are in grams (g). We must match them.
1 kg = 1000 g
โ Conversion:
\[ 12 \text{ kg} = 12 \times 1000 = 12\,000 \text{ g} \]Step 2: Calculate Daily Food Usage
โ Working:
3 meals per day, 105 g per meal.
\[ 3 \times 105 = 315 \text{ g per day} \]Step 3: Calculate How Many Days it Lasts
โ Division:
\[ 12\,000 \div 315 = 38.095… \]The food lasts for 38 full days.
Step 4: Convert Days to Weeks
โ Division:
There are 7 days in a week.
\[ 38.095 \div 7 = 5.44… \]The question asks for complete weeks.
๐ฏ Final Answer:
5 complete weeks
โ (P1 for conversion, P1 for daily usage, P1 for total days/weeks calculation, P1 for division by 7, A1)
Question 10 (3 marks)
Here is a polygon.
(a) Write down the mathematical name of this polygon.
Here is a prism.
Each edge of the prism has a length of 7.5 cm.
(b) Work out the total length of the edges of the prism.
Worked Solution
Part (a): Naming the Shape
The shape has 5 straight sides.
A 5-sided polygon is called a Pentagon.
Answer: Pentagon
โ (B1)
Part (b): Total Edge Length
๐ก Strategy: We need to count the total number of edges on a pentagonal prism and multiply by the length of one edge.
Counting Edges:
- Front face (Pentagon): 5 edges
- Back face (Pentagon): 5 edges
- Connecting edges (Rectangular faces): 5 edges
Total Edges: \( 5 + 5 + 5 = 15 \)
โ Calculation:
Each edge is 7.5 cm.
\[ 15 \times 7.5 \]Using calculator: 112.5
๐ฏ Final Answer:
112.5 cm
โ (P1 for identification of edges, A1)
Question 11 (2 marks)
There are only red counters, blue counters and green counters in a bag.
number of red counters : number of blue counters : number of green counters = \( 2 : 16 : 7 \)
What fraction of the counters in the bag are green counters?
Worked Solution
Step 1: Find Total Parts
๐ก Strategy: To find a fraction, we need the “part” we are interested in (green) and the “whole” (total counters).
โ Calculation:
\[ \text{Total parts} = 2 + 16 + 7 = 25 \]Step 2: Write the Fraction
We want the fraction of green counters.
Green parts = 7
โ Result:
\[ \text{Fraction} = \frac{\text{Green Parts}}{\text{Total Parts}} = \frac{7}{25} \]๐ฏ Final Answer:
\( \frac{7}{25} \)
โ (M1, A1)
Question 12 (2 marks)
A chess match lasted \( 3\frac{1}{4} \) hours.
The match finished at 14:10
At what time did the chess match start?
Worked Solution
Step 1: Convert Fraction to Minutes
๐ก Strategy: It’s easier to subtract time if we know the minutes.
\( \frac{1}{4} \) of an hour is \( 60 \div 4 = 15 \) minutes.
So, the match lasted 3 hours and 15 minutes.
Step 2: Subtract Time
โ Working backwards from 14:10:
1. Subtract the 3 hours first:
\( 14:10 – 3 \text{ hours} = 11:10 \)
2. Now subtract the 15 minutes:
\( 11:10 – 10 \text{ minutes} = 11:00 \)
\( 11:00 – 5 \text{ minutes} = 10:55 \)
๐ฏ Final Answer:
10:55 (or 10:55 am)
โ (M1, A1)
Question 13 (2 marks)
(a) Simplify \( 8h^3 + 14h^3 – 2h^3 \)
(b) Simplify \( (9y + 12y) \div 3 \)
Worked Solution
Part (a): Collecting Like Terms
๐ก Rule: All terms have \( h^3 \), so we can just add/subtract the coefficients (the numbers in front).
โ Working:
\[ 8 + 14 – 2 = 20 \]Attach the \( h^3 \) back:
\[ 20h^3 \]Answer: \( 20h^3 \)
โ (B1)
Part (b): Simplify and Divide
๐ก Order of Operations: Simplify inside the brackets first.
Step 1: Inside brackets
\[ 9y + 12y = 21y \]Step 2: Divide by 3
\[ 21y \div 3 = 7y \]Answer: \( 7y \)
โ (B1)
Question 14 (2 marks)
Write the following numbers in order of size.
Start with the smallest number.
\( \frac{7}{12} \quad 0.56 \quad 57\% \quad \frac{6}{11} \quad 0.558 \)
Worked Solution
Step 1: Convert Everything to Decimals
๐ก Strategy: To compare different formats (fractions, percentages, decimals), convert them all to decimals with 3 decimal places.
โ Calculations:
- \( \frac{7}{12} = 7 \div 12 = \mathbf{0.583…} \)
- \( 0.56 = \mathbf{0.560} \)
- \( 57\% = 0.57 = \mathbf{0.570} \)
- \( \frac{6}{11} = 6 \div 11 = \mathbf{0.545…} \)
- \( 0.558 = \mathbf{0.558} \)
Step 2: Compare and Order
Ordered list (Smallest to Largest):
- 0.545… (\( \frac{6}{11} \))
- 0.558
- 0.560 (\( 0.56 \))
- 0.570 (\( 57\% \))
- 0.583… (\( \frac{7}{12} \))
๐ฏ Final Answer:
\( \frac{6}{11}, \quad 0.558, \quad 0.56, \quad 57\%, \quad \frac{7}{12} \)
โ (M1 for conversion, A1 for correct order)
Question 15 (5 marks)
A travel agent sold 100 holidays in April.
Each of these holidays was in the UK or was abroad.
64 of the 100 holidays were sold to families.
The rest of the holidays were sold to couples.
11 of the 18 holidays abroad were sold to couples.
(a) Use this information to complete the frequency tree.
One of the holidays sold to a family is chosen at random.
(b) Find the probability that this holiday was not abroad.
Worked Solution
Part (a): Completing the Tree
๐ก Analyze the Clues:
- “64 sold to families” โ Top middle circle = 64.
- “Rest sold to couples” โ \( 100 – 64 = 36 \) โ Bottom middle circle = 36.
- “11 of the 18 holidays abroad were sold to couples”
This tells us two things:- Couples/Abroad = 11
- Total Abroad = 18
โ Calculating remaining numbers:
Families/Abroad: Total Abroad (18) – Couples/Abroad (11) = 7.
Families/UK: Total Families (64) – Families/Abroad (7) = 57.
Couples/UK: Total Couples (36) – Couples/Abroad (11) = 25.
Check: \( 57 + 7 + 25 + 11 = 100 \). Correct.
Part (b): Probability
๐ก Identify the Sample Space:
The question says “One of the holidays sold to a family is chosen”.
So, our denominator is the total number of families: 64.
๐ก Identify the Success criteria:
We want “not abroad”, which means UK.
Number of families going to UK: 57.
Answer:
\[ \frac{57}{64} \]โ (M1, A1)
Question 16 (2 marks)
Solve \( \frac{x}{7} + 9 = 4 \)
Worked Solution
Step 1: Isolate the fraction
๐ก Strategy: We need to get \( x \) on its own. First, move the \( +9 \) to the other side by subtracting 9.
โ Working:
\[ \frac{x}{7} = 4 – 9 \] \[ \frac{x}{7} = -5 \]Step 2: Remove the denominator
Since \( x \) is divided by 7, we multiply both sides by 7.
โ Working:
\[ x = -5 \times 7 \] \[ x = -35 \]๐ฏ Final Answer:
\( x = -35 \)
โ (M1, A1)
Question 17 (3 marks)
Blake works 32 hours a week in the UK.
She is paid ยฃ473.28 per week.
Blake applies for a job in Australia.
The rate of pay is 26.40 Australian dollars per hour.
ยฃ1 = 1.796 Australian dollars
Blake thinks the rate of pay in Australia is greater than the rate of pay in the UK.
Is Blake correct?
You must show how you get your answer.
Worked Solution
Step 1: Calculate UK Hourly Rate
๐ก Strategy: To compare, we need the hourly rate for both jobs in the same currency.
โ UK Rate Calculation:
\[ \text{Rate} = \frac{\text{Total Pay}}{\text{Hours}} \] \[ \text{Rate} = \frac{473.28}{32} \]Calculator: \( 473.28 \div 32 = ยฃ14.79 \text{ per hour} \)
Step 2: Convert Currencies to Compare
We can either convert the UK rate to Dollars OR the Australian rate to Pounds.
Method A: Convert UK rate (ยฃ) to Dollars ($)
โ Working:
\[ 14.79 \times 1.796 = 26.56284 \]So, the UK job pays $26.56 per hour.
Step 3: Compare and Conclude
โ Comparison:
UK Rate: $26.56
Australia Rate: $26.40
\( 26.56 > 26.40 \)
๐ฏ Final Answer:
No, Blake is not correct.
The UK pay ($26.56) is higher than the Australia pay ($26.40).
โ (M1 for UK rate, M1 for conversion, C1 for conclusion)
Question 18 (5 marks)
Here is a shape made from a rectangle and a triangle.
The shape has exactly one line of symmetry.
The area of the rectangle is 3.5 times the area of the triangle.
The width of the rectangle is \( w \) cm.
Work out the value of \( w \).
Worked Solution
Step 1: Find the Triangle Base
๐ก Using Symmetry: Since the shape has a line of symmetry, the gaps on the left and right of the triangle must be equal.
Left gap = 3.8 cm
Right gap = 3.8 cm
Total width = 14 cm
โ Calculation:
\[ \text{Base of Triangle} = 14 – 3.8 – 3.8 \] \[ \text{Base} = 14 – 7.6 = 6.4 \text{ cm} \]Step 2: Area of the Triangle
โ Formula: \( \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} \)
\[ \text{Area} = 0.5 \times 6.4 \times 6 \] \[ \text{Area} = 19.2 \text{ cm}^2 \]Step 3: Area of the Rectangle
We are told: “Area of the rectangle is 3.5 times the area of the triangle”.
โ Calculation:
\[ \text{Area}_{\text{rect}} = 3.5 \times 19.2 \] \[ \text{Area}_{\text{rect}} = 67.2 \text{ cm}^2 \]Step 4: Find \( w \)
โ Working:
\[ \text{Area}_{\text{rect}} = \text{length} \times \text{width} \] \[ 67.2 = 14 \times w \] \[ w = \frac{67.2}{14} \] \[ w = 4.8 \]๐ฏ Final Answer:
\( w = 4.8 \)
โ (P1 missing length, P1 area tri, P1 area rect, P1 solve, A1)
Question 19 (3 marks)
The front elevation of a cuboid is shown on the centimetre grid below.
The volume of the cuboid is 224 cm3.
On the grid, draw the plan of the cuboid.
Worked Solution
Step 1: Identify Dimensions from Elevation
The front elevation shows the Length and Height.
Counting the squares (1 square = 1 cm):
- Length = 8 cm
- Height = 4 cm
Step 2: Calculate the Depth (Width)
โ Formula: \( \text{Volume} = \text{Length} \times \text{Depth} \times \text{Height} \)
\[ 224 = 8 \times \text{Depth} \times 4 \] \[ 224 = 32 \times \text{Depth} \] \[ \text{Depth} = \frac{224}{32} \] \[ \text{Depth} = 7 \text{ cm} \]Step 3: Draw the Plan View
The Plan is the view from the top.
It shows the Length (8 cm) and the Depth (7 cm).
We need to draw a rectangle that is 8 squares wide and 7 squares high.
๐ฏ Final Answer:
Draw a rectangle 8 cm by 7 cm (or 7 cm by 8 cm) on the grid.
โ (M1 dims, M1 depth, C1 drawing)
Question 20 (2 marks)
(a) Write 468 000 in standard form.
(b) Write \( 5.037 \times 10^{-4} \) as an ordinary number.
Worked Solution
Part (a): To Standard Form
๐ก Rule: \( A \times 10^n \) where \( 1 \le A < 10 \).
Decimal point moves from the end (468000.) to between the 4 and 6 (4.68).
It moves 5 places to the left.
Answer: \( 4.68 \times 10^5 \)
โ (B1)
Part (b): From Standard Form
๐ก Rule: Negative power means the number is small (less than 1).
Move the decimal point 4 places to the left.
โ Working:
5.037
0.5037 (1 jump)
0.05037 (2 jumps)
0.005037 (3 jumps)
0.0005037 (4 jumps)
Answer: 0.0005037
โ (B1)
Question 21 (2 marks)
Here is a biased spinner.
The table shows the probabilities that when the spinner is spun it will land on A, on B, on C and on D.
| Letter | A | B | C | D |
|---|---|---|---|---|
| Probability | 0.4 | 0.21 | 0.32 | 0.07 |
Luka will spin the spinner 200 times.
Work out an estimate for the number of times the spinner will land on A.
Worked Solution
Step 1: Understanding Expected Frequency
๐ก Formula: To find the expected number of times an event happens, we multiply the probability of the event by the number of trials.
\[ \text{Expected} = \text{Probability} \times \text{Number of Spins} \]Step 2: Calculation
โ Working:
- Probability of A = 0.4
- Number of spins = 200
Calculation Trick: \( 0.4 \times 100 = 40 \), so \( 0.4 \times 200 = 80 \).
๐ฏ Final Answer:
80
โ (M1, A1)
Question 22 (4 marks)
Seija works at a weather station.
The table gives information about the temperature, \( T \) ยฐC, at midday for each of 50 cities in the UK on Tuesday.
| Temperature (\( T \) ยฐC) | Frequency |
|---|---|
| \( 10 < T \le 15 \) | 2 |
| \( 15 < T \le 20 \) | 8 |
| \( 20 < T \le 25 \) | 13 |
| \( 25 < T \le 30 \) | 21 |
| \( 30 < T \le 35 \) | 6 |
(a) Calculate an estimate for the mean temperature.
Seija says,
(b) Is Seija correct?
Give a reason for your answer.
Worked Solution
Part (a): Estimated Mean
๐ก Strategy:
- Find the Midpoint of each group (because we don’t know exact temperatures).
- Multiply Midpoint by Frequency (\( f \times x \)).
- Sum these totals and divide by the total frequency (50).
โ Working Table:
| Group | Midpoint (\(x\)) | Freq (\(f\)) | \(f \times x\) |
|---|---|---|---|
| 10-15 | 12.5 | 2 | 25 |
| 15-20 | 17.5 | 8 | 140 |
| 20-25 | 22.5 | 13 | 292.5 |
| 25-30 | 27.5 | 21 | 577.5 |
| 30-35 | 32.5 | 6 | 195 |
| Totals | 50 | 1230 |
\[ \text{Mean} = \frac{1230}{50} = 24.6 \]
Answer: 24.6 ยฐC
โ (M1, M1, A1)
Part (b): Evaluating Seija’s Statement
๐ก Determining the Median Position:
Total data points = 50.
The median is at position \( \frac{50+1}{2} = 25.5 \), so between the 25th and 26th values.
Counting Cumulative Frequency:
- 1st group: 2 values (Total 2)
- 2nd group: 8 values (Total 10)
- 3rd group: 13 values (Total 23) ← Still not reached 25.5
- 4th group (\( 25 < T \le 30 \)): 21 values (Total 44) ← The 25th and 26th values are in here!
Answer:
No.
Reason: The median is in the interval \( 25 < T \le 30 \), not the interval \( 20 < T \le 25 \).
(Alternative reason: Seija did not account for the frequency of each group, only the position of the groups.)
โ (C1)
Question 23 (4 marks)
Jenna is asked to show the inequality \( -3 < x \le 4 \) on a number line.
Here is her answer.
(a) Write down two mistakes Jenna has made.
(b) Work out the greatest integer that satisfies the inequality
\( 5y – 7 < 16 \)
Worked Solution
Part (a): Identifying Mistakes
๐ก Compare:
Correct Inequality: \( -3 < x \le 4 \)
- Starts at -3.
- End point 4 is inclusive (\( \le \)), so circle should be filled.
Jenna’s Drawing:
- Starts at -2.
- End point 4 has an empty circle (not inclusive).
Mistake 1: She started the line at -2, but it should start at -3.
Mistake 2: The circle at 4 should be solid (filled in) because it is \( \le \).
โ (C1, C1)
Part (b): Solving Inequality
โ Solve for \( y \):
\[ 5y – 7 < 16 \]Add 7 to both sides:
\[ 5y < 23 \]Divide by 5:
\[ y < \frac{23}{5} \] \[ y < 4.6 \]We need the greatest integer (whole number) that is less than 4.6.
The integers less than 4.6 are 4, 3, 2…
The largest is 4.
Answer: 4
โ (M1 solve, A1)
Question 24 (3 marks)
Ali buys packs of balloons and boxes of pencils.
There are 30 balloons in each pack.
There are 24 pencils in each box.
Ali buys exactly the same number of balloons and pencils.
Work out how many packs of balloons and how many boxes of pencils she could have bought.
You must show all your working.
Worked Solution
Step 1: Identify the Problem Type
๐ก Concept: We need a number that both 30 and 24 divide into perfectly.
This is a Lowest Common Multiple (LCM) problem.
Step 2: Find the LCM of 30 and 24
Method 1: List Multiples
Multiples of 30: 30, 60, 90, 120, 150…
Multiples of 24: 24, 48, 72, 96, 120, 144…
The lowest common multiple is 120.
Step 3: Calculate Quantities
We need 120 balloons and 120 pencils.
โ Packs of Balloons:
\[ 120 \div 30 = 4 \]โ Boxes of Pencils:
\[ 120 \div 24 = 5 \]๐ฏ Final Answer:
4 packs of balloons
5 boxes of pencils
โ (P1 LCM method, P1 calculate common multiple, A1 correct pair)
Question 25 (2 marks)
A company orders a large number of plates from a factory.
It would take 30 hours to make all the plates using 4 machines.
How many machines are needed to make all the plates in 6 hours?
Worked Solution
Step 1: Understanding Inverse Proportion
๐ก Logic: If we want to finish faster (fewer hours), we need more machines.
First, calculate the total “machine-hours” needed to do the job.
โ Total Work Required:
\[ 4 \text{ machines} \times 30 \text{ hours} = 120 \text{ machine-hours} \]This means one machine would take 120 hours.
Step 2: Calculate Machines for 6 Hours
โ Division:
\[ \frac{\text{Total Work}}{\text{Target Time}} = \frac{120}{6} \] \[ 120 \div 6 = 20 \]๐ฏ Final Answer:
20 machines
โ (M1, A1)
Question 26 (3 marks)
Riley travelled by car and by aeroplane.
He travelled 143 miles by car at an average speed of 55 miles per hour.
Riley then travelled for 5 hours and 20 minutes by aeroplane.
Work out, in hours and minutes, Rileyโs total travelling time.
Worked Solution
Step 1: Calculate Car Journey Time
๐ก Formula: \( \text{Time} = \frac{\text{Distance}}{\text{Speed}} \)
โ Calculation:
\[ \text{Time}_{\text{car}} = \frac{143}{55} \]Calculator: \( 143 \div 55 = 2.6 \text{ hours} \)
Step 2: Convert Decimal Hours to Minutes
We have 2 full hours and 0.6 of an hour.
To convert 0.6 hours to minutes, multiply by 60.
โ Working:
\[ 0.6 \times 60 = 36 \text{ minutes} \]So, Car Time = 2 hours 36 minutes.
Step 3: Add Plane Time
โ Addition:
Car: 2 h 36 min
Plane: 5 h 20 min
Minutes: \( 36 + 20 = 56 \text{ min} \)
Hours: \( 2 + 5 = 7 \text{ h} \)
๐ฏ Final Answer:
7 hours 56 minutes
โ (P1 car time, P1 conversion, A1)
Question 27 (3 marks)
The diagram shows a solid cube placed on a horizontal table.
The pressure on the table due to the cube is 3.5 newtons/cmยฒ
The force exerted by the cube on the table is 504 newtons.
Show that the total surface area of the cube is less than 900 cmยฒ
Worked Solution
Step 1: Calculate Area of One Face
๐ก Strategy: Rearrange the formula: \( \text{Area} = \frac{\text{Force}}{\text{Pressure}} \)
This gives us the area of the base of the cube (the part touching the table).
โ Calculation:
\[ \text{Area} = \frac{504}{3.5} \]Calculator: 144 cmยฒ
Step 2: Calculate Total Surface Area
A cube has 6 identical square faces.
We know the area of one face is 144 cmยฒ.
โ Calculation:
\[ \text{Total Area} = 144 \times 6 \] \[ \text{Total Area} = 864 \text{ cm}^2 \]Step 3: Conclusion
โ Compare:
864 cmยฒ is less than 900 cmยฒ.
\( 864 < 900 \)
Answer: Shown correctly.
โ (M1 find area of face, M1 total area, C1 conclusion)
Question 28 (3 marks)
The line L is shown on the grid.
Find an equation for L.
Worked Solution
Step 1: Standard Form
The equation of a straight line is \( y = mx + c \)
- \( m \) is the gradient (slope).
- \( c \) is the y-intercept (where it crosses the y-axis).
Step 2: Find \( c \) (y-intercept)
Look at the graph. The line crosses the vertical y-axis at 3.
โ Result:
\[ c = 3 \]Step 3: Find \( m \) (Gradient)
๐ก Strategy: Pick two points on the line and check the “Rise over Run”.
Point 1: \( (0, 3) \)
Point 2: \( (1, 1) \)
โ Calculation:
Change in \( y \) (Rise): From 3 down to 1 is -2.
Change in \( x \) (Run): From 0 across to 1 is 1.
\[ m = \frac{\text{Change in } y}{\text{Change in } x} = \frac{-2}{1} = -2 \]๐ฏ Final Answer:
\( y = -2x + 3 \)
โ (M1 gradient, M1 intercept, A1 equation)
Question 29 (4 marks)
\( A \), \( B \), \( C \) and \( D \) are points on a circle such that \( ABCD \) is a square.
The square \( ABCD \) has sides of length 3.5 cm.
Calculate the circumference of the circle.
Give your answer correct to 1 decimal place.
You must show all your working.
Worked Solution
Step 1: Relate Square to Circle
๐ก Key Insight: The diagonal of the square is equal to the diameter of the circle.
We can use Pythagoras’ Theorem to find the diagonal.
Step 2: Find the Diameter
โ Pythagoras: \( a^2 + b^2 = c^2 \)
\[ 3.5^2 + 3.5^2 = \text{Diameter}^2 \] \[ 12.25 + 12.25 = 24.5 \] \[ \text{Diameter} = \sqrt{24.5} \] \[ \text{Diameter} = 4.9497… \text{ cm} \]Step 3: Calculate Circumference
๐ก Formula: \( C = \pi \times d \)
โ Calculation:
\[ C = \pi \times 4.9497… \]Calculator: \( 15.5498… \)
๐ฏ Final Answer:
Round to 1 decimal place:
15.6 cm
โ (P1 Pythagoras, P1 find diameter, P1 circumference formula, A1 answer)