Grade-8 Practice Test
📘 CBSE Curriculum 2025–26
Grade 8 Mathematics
Full-Length Mock Practice Test
🔢 Rational Numbers
√ Squares & Square Roots
🔣 Algebraic Expressions & Identities
📐 Mensuration
⚡ Exponents & Powers
🔍 Factorisation
↕️ Direct & Inverse Variation
📈 Introduction to Graphs
80
Total Marks
3 hrs
Duration
4
Sections
40
Questions
Name
Roll No.
School
Date
Marks Obtained
/ 80
Grade 8 Mathematics — Mock Practice Test
CBSE Pattern | 3 Hours | 80 Marks
📋 General Instructions
- This question paper consists of 40 questions divided into four sections: A, B, C, and D.
- Section A — 20 MCQs of 1 mark each (No negative marking).
- Section B — 6 questions of 2 marks each. Short-answer questions.
- Section C — 8 questions of 3 marks each. Long-answer type I.
- Section D — 6 questions of 5 marks each. Long-answer type II (includes Case-Based / Value-Based questions).
- All questions are compulsory. However, internal choices have been provided wherever applicable.
- Use of calculator is NOT permitted.
- Draw neat labelled diagrams wherever required. Untidy diagrams may result in loss of marks.
- Write your Name and Roll Number clearly on the top of the Answer Sheet.
- Read each question carefully before answering. Manage your time wisely.
| Section | Type | No. of Questions | Marks per Question | Total Marks | Topics Covered |
|---|---|---|---|---|---|
| 🅐 Section A | Multiple Choice (MCQ) | 20 | 1 | 20 | All 8 topics |
| 🅑 Section B | Short Answer – I | 6 | 2 | 12 | All 8 topics |
| 🅒 Section C | Short Answer – II | 8 | 3 | 24 | All 8 topics |
| 🅓 Section D | Long Answer (Case-Based) | 6 | 4 + 1 HOT* | 24 | All 8 topics |
| ⭐ TOTAL | 80 | — | |||
*HOT = Higher Order Thinking | Internal choices are given in Section C and Section D.
💡 Time Management Tip: Spend ~30 min on Section A, ~20 min on Section B, ~45 min on Section C, and ~65 min on Section D. Reserve 20 minutes for revision at the end.
Topic-wise Weightage
| Topic | Chapter | Marks Approx. |
|---|---|---|
| Rational Numbers | Ch. 1 | 8 |
| Squares & Square Roots | Ch. 3 | 8 |
| Algebraic Expressions & Identities | Ch. 8 | 10 |
| Mensuration | Ch. 9 | 12 |
| Exponents & Powers | Ch. 10 | 8 |
| Factorisation | Ch. 12 | 10 |
| Direct & Inverse Variation | Ch. 11 | 12 |
| Introduction to Graphs | Ch. 13 | 12 |
| Total | 80 | |
Section A — Multiple Choice Questions
20 Questions × 1 Mark = 20 Marks
📌 Instructions for Section A
- Each question has four options (A), (B), (C), (D). Choose the correct one.
- Each question carries 1 mark. There is no negative marking.
- Fill the correct circle (⭕) on your answer sheet.
🔢 Rational Numbers (Q1–Q3)
Q1
Which of the following is the additive inverse of −7/11?
(A) 7/11
(B) −7/11
(C) 11/7
(D) −11/7
1
mark
Q2
Riya divided her pocket money of ₹240 equally into 5 parts. She donated 3 parts to a charity fund. The amount donated, expressed as a fraction of the total, is:
(A) 3/5
(B) 2/5
(C) ₹144
(D) Both (A) and (C)
1
mark
Q3
How many rational numbers lie between 1/3 and 1/2?
(A) 1
(B) 3
(C) 10
(D) Infinitely many
1
mark
√ Squares & Square Roots (Q4–Q6)
Q4
A school auditorium has 2025 chairs arranged in a square formation (equal rows and columns). The number of chairs in each row is:
(A) 25
(B) 35
(C) 45
(D) 55
1
mark
Q5
Which of the following cannot be the units digit of a perfect square?
(A) 1
(B) 4
(C) 8
(D) 9
1
mark
Q6
The smallest number by which 180 must be multiplied to make it a perfect square is:
(A) 2
(B) 3
(C) 4
(D) 5
1
mark
🔣 Algebraic Expressions & Identities (Q7–Q9)
Q7
Using the identity (a+b)² = a² + 2ab + b², the value of 103² is:
(A) 10,506
(B) 10,609
(C) 10,309
(D) 10,600
1
mark
Q8
If x + 1/x = 6, then the value of x² + 1/x² is:
(A) 36
(B) 34
(C) 38
(D) 32
1
mark
Q9
The product 49 × 51 using the identity (a+b)(a−b) = a²−b² equals:
(A) 2,500
(B) 2,401
(C) 2,499
(D) 2,599
1
mark
📐 Mensuration (Q10–Q12)
Q10
A farmer has a trapezoidal field with parallel sides of 30 m and 20 m, and a height of 15 m. The area of the field is:
(A) 300 m²
(B) 375 m²
(C) 450 m²
(D) 600 m²
1
mark
Q11
The total surface area of a cuboid with length = 8 cm, breadth = 5 cm, and height = 4 cm is:
(A) 160 cm²
(B) 184 cm²
(C) 204 cm²
(D) 256 cm²
1
mark
Q12
A cylindrical water tank has radius = 7 m and height = 10 m. The volume of water it can hold (use π = 22/7) is:
(A) 1,540 m³
(B) 1,230 m³
(C) 2,200 m³
(D) 1,000 m³
1
mark
⚡ Exponents & Powers (Q13–Q14)
Q13
The value of (2⁻³ × 3²) / (2² × 3⁻¹) is:
(A) 27/32
(B) 9/32
(C) 32/27
(D) 3/8
1
mark
Q14
The mass of Earth is approximately 5,970,000,000,000,000,000,000,000 kg. In standard form (scientific notation), this is written as:
(A) 5.97 × 10²⁴ kg
(B) 59.7 × 10²³ kg
(C) 5.97 × 10²³ kg
(D) 5.97 × 10²⁵ kg
1
mark
🔍 Factorisation (Q15–Q16)
Q15
The factorised form of 4a² − 9b² is:
(A) (4a + 9b)(4a − 9b)
(B) (2a − 3b)²
(C) (2a + 3b)(2a − 3b)
(D) (2a + 3b)²
1
mark
Q16
The common factor of 12a²b, 18ab², and 24a²b² is:
(A) 6ab
(B) 12ab
(C) 6a²b²
(D) 2ab
1
mark
↕️ Direct & Inverse Variation (Q17–Q18)
Q17
A car travels 240 km in 4 hours. If it maintains the same speed, the time taken to travel 360 km is:
(A) 5 hours
(B) 6 hours
(C) 7 hours
(D) 8 hours
1
mark
Q18
If 8 workers can build a wall in 12 days, how many days will 16 workers take (assuming inverse variation)?
(A) 24 days
(B) 6 days
(C) 4 days
(D) 8 days
1
mark
📈 Introduction to Graphs (Q19–Q20)
Q19
A point P lies on the y-axis. Its x-coordinate must be:
(A) Any number
(B) 0
(C) 1
(D) −1
1
mark
Q20
The graph of a direct proportion between two variables x and y always passes through:
(A) (1, 1)
(B) The origin (0, 0)
(C) (0, 1)
(D) (1, 0)
1
mark
Section B — Short Answer Questions
6 Questions × 2 Marks = 12 Marks
📌 Instructions for Section B
- Each question carries 2 marks.
- Show all working / steps clearly to earn full marks.
🔢 Rational Numbers
Q21
The temperature in Shimla on Monday was −4.5°C. On Tuesday, it dropped further by 3/2°C and on Wednesday it rose by 7/4°C. What was the temperature on Wednesday? Express your answer as a fraction.
2
marks
√ Squares & Square Roots
Q22
A gardener wants to fence a square plot of area 2116 m². Find the length of fencing wire required and the cost of fencing at ₹25 per metre.
2
marks
⚡ Exponents & Powers
Q23
Simplify and express with positive exponents:
[( 5⁻² × 3³) / (5³ × 3⁻²)]
⭐ Hint: Use the law aᵐ × aⁿ = aᵐ⁺ⁿ and a⁻ⁿ = 1/aⁿ
2
marks
🔍 Factorisation
Q24
Factorise completely: 15x²y − 20xy² + 25xy
2
marks
↕️ Direct Variation
Q25
A motorbike consumes 4 litres of petrol to cover 120 km. Using the concept of direct proportion, find how far it can travel on 11 litres of petrol. Set up the proportion clearly.
2
marks
📈 Introduction to Graphs
Q26
Plot the following points on the grid below and write the quadrant (or axis) each point lies in:
A(3, −2), B(−4, 1), C(0, 5), D(−3, −3)
A(3, −2), B(−4, 1), C(0, 5), D(−3, −3)
2
marks
Section C — Short Answer Questions (LA-I)
8 Questions × 3 Marks = 24 Marks
📌 Instructions for Section C
- Each question carries 3 marks. Show complete working.
- Some questions have internal choice (OR) — attempt only ONE of the two options.
🔢 Rational Numbers
Q27
A water pipe fills 3/8 of a tank in 1 hour. Due to a leak, the tank loses 1/12 of its capacity per hour.
(a) What fraction of the tank is filled in 1 hour, considering the leak?
(b) How many hours will it take to fill the complete tank?
(c) Represent the net filling rate as a point on a number line (draw it).
(a) What fraction of the tank is filled in 1 hour, considering the leak?
(b) How many hours will it take to fill the complete tank?
(c) Represent the net filling rate as a point on a number line (draw it).
3
marks
√ Squares & Square Roots
Q28
[Internal Choice]
Find the square root of 108900 using the prime factorisation method. Also verify your answer.
OR
Find the least number that must be added to 6412 to make it a perfect square. Also find the square root of the resulting number using the long division method.
Find the square root of 108900 using the prime factorisation method. Also verify your answer.
OR
Find the least number that must be added to 6412 to make it a perfect square. Also find the square root of the resulting number using the long division method.
3
marks
🔣 Algebraic Expressions & Identities
Q29
A rectangular garden has its length represented by (3x + 4) m and breadth by (2x − 1) m.
(a) Find its area in terms of x.
(b) If x = 5 m, find the actual area and perimeter.
(c) The cost of laying grass is ₹12 per m². Find the total cost.
(a) Find its area in terms of x.
(b) If x = 5 m, find the actual area and perimeter.
(c) The cost of laying grass is ₹12 per m². Find the total cost.
3
marks
📐 Mensuration
Q30
[Internal Choice]
A swimming pool is 50 m long, 20 m wide, and 2.5 m deep. Find:
A solid iron cylinder has a diameter of 14 cm and height of 20 cm. Find its total surface area and volume (use π = 22/7).
A swimming pool is 50 m long, 20 m wide, and 2.5 m deep. Find:
- Volume of water it can hold (in litres; 1 m³ = 1000 litres)
- The curved surface area of the four walls
- Cost of painting the walls and floor at ₹8 per m²
A solid iron cylinder has a diameter of 14 cm and height of 20 cm. Find its total surface area and volume (use π = 22/7).
Cylinder (not to scale)
3
marks
⚡ Exponents & Powers
Q31
A scientist measures two microscopic particles:
Particle A: diameter = 4.5 × 10⁻⁷ m | Particle B: diameter = 9 × 10⁻⁵ m
(a) How many times larger is Particle B than Particle A?
(b) Express the total combined diameter in standard form.
(c) Simplify: (3⁻² × 4³) ÷ (3² × 4⁻¹)
Particle A: diameter = 4.5 × 10⁻⁷ m | Particle B: diameter = 9 × 10⁻⁵ m
(a) How many times larger is Particle B than Particle A?
(b) Express the total combined diameter in standard form.
(c) Simplify: (3⁻² × 4³) ÷ (3² × 4⁻¹)
3
marks
🔍 Factorisation
Q32
[Internal Choice]
Factorise the following completely, using suitable methods:
(a) x² + 8x + 15 (b) 49p² − 64q² (c) a²b − ab² + 2ab
OR
Divide (4x³ − 8x² + 6x) by 2x using the division algorithm, and verify your answer.
Factorise the following completely, using suitable methods:
(a) x² + 8x + 15 (b) 49p² − 64q² (c) a²b − ab² + 2ab
OR
Divide (4x³ − 8x² + 6x) by 2x using the division algorithm, and verify your answer.
3
marks
↕️ Direct & Inverse Variation
Q33
Study the table and answer the questions:
(a) Is this direct or inverse variation? Justify.
(b) Find the missing values.
(c) How many workers are needed to complete the job in 6 days?
| Number of workers (x) | 4 | 6 | 8 | 12 |
|---|---|---|---|---|
| Days to complete a job (y) | 24 | ? | ? | 8 |
(b) Find the missing values.
(c) How many workers are needed to complete the job in 6 days?
3
marks
📈 Introduction to Graphs
Q34
The following table shows the temperature (°C) of a city at different hours of a day:
(a) Plot this data as a line graph on the grid below.
(b) Between which two time slots did the temperature rise the most?
(c) Find the average temperature for the day.
| Time (Hours) | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM |
|---|---|---|---|---|---|
| Temp (°C) | 15 | 20 | 30 | 28 | 22 |
(b) Between which two time slots did the temperature rise the most?
(c) Find the average temperature for the day.
3
marks
Section D — Long Answer / Case-Based Questions
6 Questions × 4+1 Marks = 24 Marks
📌 Instructions for Section D
- Each question carries 4 marks. One sub-part (marked ⭐) in each question is an HOT (Higher Order Thinking) question worth 1 additional mark.
- Show all steps, formulae, and working clearly.
- Draw diagrams wherever required — neat and labelled diagrams earn marks.
- Internal choices are provided — attempt only ONE of the two options.
📦 Case Study 1 — The Community Vegetable Garden (Rational Numbers + Mensuration)
Q35
📖 Case: The residents of an apartment complex decided to build a community vegetable garden on a rectangular plot of land. The plot is (15/4) m long and (8/3) m wide. They divided it into sections:
(a) Calculate the total area of the garden (in m²). [1 mark]
(b) Find the area used for tomatoes and spinach separately. [1 mark]
(c) What fraction of the total area is used for carrots? Find the area in m². [1 mark]
⭐ (d) HOT: If the cost of fencing the entire plot is ₹120 per metre, and they also want to put a divider between tomatoes and spinach (height = 1 m, length = breadth of garden), what is the total cost of fencing + divider at the same rate? [1 mark]
- Tomatoes: 2/5 of the total area
- Spinach: 1/3 of the total area
- Carrots: remaining area
Community Garden Layout (not to scale)
(b) Find the area used for tomatoes and spinach separately. [1 mark]
(c) What fraction of the total area is used for carrots? Find the area in m². [1 mark]
⭐ (d) HOT: If the cost of fencing the entire plot is ₹120 per metre, and they also want to put a divider between tomatoes and spinach (height = 1 m, length = breadth of garden), what is the total cost of fencing + divider at the same rate? [1 mark]
4+1
marks
🏗️ Case Study 2 — The School Sports Day (Squares & Identities)
Q36
📖 Case: For the Annual Sports Day, the school ground needs to be prepared. A square running track is laid out such that its area is 12,769 m². A rectangular long-jump pit measures (x + 5) m × (x − 5) m. The school uses algebraic identities to calculate dimensions quickly.
(a) Find the side length of the square track using the square root method. [1 mark]
(b) Find the perimeter of the track and the cost of painting it at ₹18 per m. [1 mark]
(c) Using identity, find the area of the long-jump pit. What does the identity used tell us geometrically? [1 mark]
⭐ (d) HOT: If the area of the long-jump pit is 144 m², find the value of x and hence the actual dimensions of the pit. Verify using the identity. [1 mark]
(a) Find the side length of the square track using the square root method. [1 mark]
(b) Find the perimeter of the track and the cost of painting it at ₹18 per m. [1 mark]
(c) Using identity, find the area of the long-jump pit. What does the identity used tell us geometrically? [1 mark]
⭐ (d) HOT: If the area of the long-jump pit is 144 m², find the value of x and hence the actual dimensions of the pit. Verify using the identity. [1 mark]
⭐ Hint: (a+b)(a−b) = a² − b²
4+1
marks
🧱 Case Study 3 — Building a Water Reservoir (Mensuration 3D)
Q37
📖 Case: A municipality plans to build two water storage structures:
(a) Find the volume of each structure. Which one holds more water? [1 mark]
(b) Find the total surface area of Structure A (cuboid). [1 mark]
(c) Find the lateral (curved) surface area of Structure B. Cost of waterproofing the curved surface = ₹15 per m². Find total cost. [1 mark]
⭐ (d) HOT: If the cylindrical tank is melted and recast into a cuboid of length 11 m and breadth 7 m, find the height of the new cuboid. [1 mark]
- Structure A: Cuboidal tank — 12 m × 8 m × 6 m
- Structure B: Cylindrical tank — radius = 7 m, height = 6 m (use π = 22/7)
(b) Find the total surface area of Structure A (cuboid). [1 mark]
(c) Find the lateral (curved) surface area of Structure B. Cost of waterproofing the curved surface = ₹15 per m². Find total cost. [1 mark]
⭐ (d) HOT: If the cylindrical tank is melted and recast into a cuboid of length 11 m and breadth 7 m, find the height of the new cuboid. [1 mark]
4+1
marks
🔬 Case Study 4 — Science Lab Calculations (Exponents & Factorisation)
Q38
📖 Case: In a school science lab, students are working on two experiments:
Experiment 1: Measuring microscopic distances. The diameter of a red blood cell is 8 × 10⁻⁶ m and the wavelength of green light is 5 × 10⁻⁷ m.
Experiment 2: Factorising polynomial expressions that model the shape of bacteria colony growth over time.
(a) How many times larger is the red blood cell than the wavelength of green light? Express in standard form. [1 mark]
(b) Simplify: [(2³ × 3²)² × (2⁻¹ × 3)³] / [2⁴ × 3⁵] [1 mark]
(c) Factorise the colony model expression: 6t² + 13t + 6 by splitting the middle term. [1 mark]
⭐ (d) HOT: The total area of a petri dish colony (cm²) at time t is given by A = 4t² − 20t + 25. Factorise this and find the value of t when A = 0. What does this represent in the context of the experiment? [1 mark]
Experiment 1: Measuring microscopic distances. The diameter of a red blood cell is 8 × 10⁻⁶ m and the wavelength of green light is 5 × 10⁻⁷ m.
Experiment 2: Factorising polynomial expressions that model the shape of bacteria colony growth over time.
(a) How many times larger is the red blood cell than the wavelength of green light? Express in standard form. [1 mark]
(b) Simplify: [(2³ × 3²)² × (2⁻¹ × 3)³] / [2⁴ × 3⁵] [1 mark]
(c) Factorise the colony model expression: 6t² + 13t + 6 by splitting the middle term. [1 mark]
⭐ (d) HOT: The total area of a petri dish colony (cm²) at time t is given by A = 4t² − 20t + 25. Factorise this and find the value of t when A = 0. What does this represent in the context of the experiment? [1 mark]
4+1
marks
🚗 Case Study 5 — Road Trip Planning (Direct & Inverse Variation)
Q39
📖 Case: The Sharma family is planning a road trip from Delhi to Jaipur. Study the data below and answer:
Also: The car gives a mileage of 15 km per litre. Petrol costs ₹106 per litre.
(a) What type of variation is shown between speed and time? Justify using the product rule. [1 mark]
(b) Complete the table by finding the missing values. [1 mark]
(c) Find the cost of petrol for the 300-km trip (at 60 km/h). [1 mark]
⭐ (d) HOT: If the family decides to increase speed by 50%, by what percentage does the travel time decrease? Show your calculation and state the type of variation used. [1 mark]
| Speed (km/h) | 40 | 60 | 80 | 120 |
|---|---|---|---|---|
| Time taken (hours) | 7.5 | 5 | ? | ? |
(a) What type of variation is shown between speed and time? Justify using the product rule. [1 mark]
(b) Complete the table by finding the missing values. [1 mark]
(c) Find the cost of petrol for the 300-km trip (at 60 km/h). [1 mark]
⭐ (d) HOT: If the family decides to increase speed by 50%, by what percentage does the travel time decrease? Show your calculation and state the type of variation used. [1 mark]
4+1
marks
📊 Case Study 6 — Tracking a Business (Introduction to Graphs)
Q40
📖 Case: Aryan started a small business selling handmade items. The table below shows his monthly profit (in ₹ hundreds):
(a) Plot this data as a bar graph on the grid provided below. Label axes clearly. [2 marks]
(b) In which month was the profit the highest? By how much did it increase from January? [1 mark]
⭐ (c) HOT: Aryan notices that if he plots his cumulative (running total) profit as a line graph, the graph resembles a direct variation after March. Compute the cumulative profit for each month and check: Is there any evidence of direct variation in the data? Justify your reasoning. [1 mark]
| Month | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Profit (₹ hundreds) | 2 | 5 | 3 | 7 | 6 | 9 |
(b) In which month was the profit the highest? By how much did it increase from January? [1 mark]
⭐ (c) HOT: Aryan notices that if he plots his cumulative (running total) profit as a line graph, the graph resembles a direct variation after March. Compute the cumulative profit for each month and check: Is there any evidence of direct variation in the data? Justify your reasoning. [1 mark]
4+1
marks
Answer Key — Section A (MCQs)
For Teacher Use Only
⚠️ THIS PAGE IS FOR TEACHER REFERENCE. DETACH BEFORE DISTRIBUTING TO STUDENTS.
Section A — Correct Answers
Q1
(A) 7/11Q2
(D) Both A & CQ3
(D) Infinitely manyQ4
(C) 45Q5
(C) 8Q6
(D) 5Q7
(B) 10,609Q8
(B) 34Q9
(C) 2,499Q10
(B) 375 m²Q11
(B) 184 cm²Q12
(A) 1,540 m³Q13
(A) 27/32Q14
(A) 5.97×10²⁴Q15
(C) (2a+3b)(2a−3b)Q16
(A) 6abQ17
(B) 6 hoursQ18
(B) 6 daysQ19
(B) 0Q20
(B) Origin (0,0)Solution Hints — Key Answers (Sections B, C, D)
| Q.No. | Key Answer / Steps | Marks |
|---|---|---|
| Q21 | Monday −4.5°C → Tuesday: −4.5 − 3/2 = −6°C → Wednesday: −6 + 7/4 = −17/4°C | 2 |
| Q22 | Side = √2116 = 46 m; Perimeter = 184 m; Cost = 184 × 25 = ₹4,600 | 2 |
| Q23 | (5⁻² × 3³)/(5³ × 3⁻²) = 3⁵/5⁵ = 243/3125 | 2 |
| Q24 | 5xy(3x − 4y + 5) | 2 |
| Q25 | 4/120 = 11/d → d = 330 km | 2 |
| Q26 | A(3,−2): Quadrant IV; B(−4,1): Quadrant II; C(0,5): y-axis; D(−3,−3): Quadrant III | 2 |
| Q27 | (a) 3/8 − 1/12 = 9/24 − 2/24 = 7/24 (b) 24/7 hours ≈ 3.43 hrs | 3 |
| Q28 | 108900 = 4 × 27225 = 4 × 9 × 3025; √108900 = 330. OR: 80²=6400; 81²=6561; add 149 → √6561=81 | 3 |
| Q29 | (a) (3x+4)(2x−1) = 6x²+5x−4 (b) x=5: Area=6(25)+25−4=171 m²; Perim=2(19+9)=56 m (c) ₹2,052 | 3 |
| Q30 | Vol=50×20×2.5=2500 m³=2,500,000 L; Wall area=2×(50+20)×2.5=350 m²; Floor=1000 m²; Cost=₹11,200 OR TSA=2π r(r+h)=2×(22/7)×7×27=1,188 cm²; V=πr²h=3,080 cm³ | 3 |
| Q31 | (a) 9×10⁻⁵/4.5×10⁻⁷ = 200 times (b) ≈9×10⁻⁵ m (c) 64/243 | 3 |
| Q32 | (a)(x+3)(x+5) (b)(7p+8q)(7p−8q) (c)ab(a−b+2) OR Dividend = 2x(2x²−4x+3); verify | 3 |
| Q33 | Inverse variation (xy=96). Missing: 16, 12; Workers for 6 days = 16 | 3 |
| Q34 | (b) Between 9AM–12PM (rise of 10°C) (c) Avg = (15+20+30+28+22)/5 = 23°C | 3 |
| Q35 | (a) 15/4 × 8/3 = 10 m² (b) Tomatoes=4 m², Spinach=10/3 m² (c) Carrots=10−4−10/3=8/3 m²; ≈2.67 m² (d) Perimeter=2(15/4+8/3)=61/6 m; divider=8/3 m; total length=61/6+8/3=77/6 m; cost=₹1,540 | 4+1 |
| Q36 | (a) √12769=113 m (b) Perimeter=452 m; Cost=₹8,136 (c) A=(x+5)(x−5)=x²−25; geometrically difference of squares (d) x²−25=144 → x=13; dimensions=18m×8m | 4+1 |
| Q37 | (a) A=576 m³, B=22/7×49×6=924 m³; B holds more (b) TSA=2(96+48+72)=432 m² (c) CSA=2×22/7×7×6=264 m²; Cost=₹3,960 (d) h=924/(11×7)=12 m | 4+1 |
| Q38 | (a) 8×10⁻⁶/5×10⁻⁷=16 (b) Simplify step by step=3/4 (c) 6t²+13t+6=(2t+3)(3t+2) (d) (2t−5)²=0 → t=5/2; colony area is zero at t=2.5 units | 4+1 |
| Q39 | (a) Inverse variation: 40×7.5=60×5=300=k (b) 80→3.75 hrs; 120→2.5 hrs (c) Distance=300km; Petrol=20L; Cost=₹2,120 (d) Speed×1.5; time decreases by 1/3 i.e. 33.3% decrease | 4+1 |
| Q40 | (b) June=₹900; increase from Jan=₹700 (c) Cumulative: 2,7,10,17,23,32; not direct variation since ratio changes; evidence of non-proportional growth | 4+1 |
📊 Performance Scoring Rubric
| Marks Range | Grade | Performance Level | Recommendation |
|---|---|---|---|
| 72 – 80 | A1 | 🏆 Outstanding | Attempt Olympiad / Competitive papers |
| 64 – 71 | A2 | 🌟 Excellent | Revise HOT questions and case studies |
| 56 – 63 | B1 | ✅ Very Good | Focus on Section D long-answer practice |
| 48 – 55 | B2 | 👍 Good | Revisit concept notes + Section C |
| 40 – 47 | C1 | 📖 Satisfactory | Re-do Section B + re-read examples |
| 32 – 39 | C2 | 💪 Needs Effort | Start from concept notes of each topic |
| Below 32 | D | 🔁 Needs Revision | Complete re-study of all chapters |
📚 Remember: Mathematics is not about memorisation — it's about understanding patterns, making connections, and solving real-life problems. Every mistake is a stepping stone to mastery. Keep going! 🌟