Direct and Inverse Proportions
21 solved questions from Class 8 Mathematics, each with the full working. Tap any question to see the step-by-step solution.
- 1 Solve the expression: 15 + 25 × 2. medium MCQ BODMAS Rule
- 2 Find the area of a rectangle with length 8 cm and breadth 5 cm. medium MCQ Area of Rectangle
- 3 What is the volume of a cube with edge 3 cm? medium MCQ Volume of Cube
- 4 Find the 10th term of AP: 2, 7, 12, ... medium MCQ Arithmetic Progression
- 5 Distance between points (0,0) and (6,8) is: medium MCQ Distance Formula
- 6 Find surface area of a sphere with radius 7 cm (π = 22/7). medium MCQ Surface Area of Sphere
- 7 If perimeter of a circle is equal to that of a square, find ratio of their areas. medium MCQ Areas Related to Circles
- 8 What is the nth term of an AP with first term a and common difference d? medium MCQ Arithmetic Progression
- 9 Coordinates of midpoint of line joining (x₁, y₁) and (x₂, y₂) is: medium MCQ Midpoint Formula
- 10 Find the value of (2⁰ + 3⁰) × 5⁰. medium MCQ Exponent Laws
- 11 What is the domain, range, or fundamental theorem introduced in 'Direct and Inverse Proportions' (Class 8 Mathematics)? medium MCQ Functions & Theorems
- 12 What is the derivative or integral formula associated with 'Direct and Inverse Proportions'? medium MCQ Calculus & Formulae
- 13 How do you find the solution set or optimum value in 'Direct and Inverse Proportions'? medium MCQ Problem Solving & Optimization
- 14 If 5 workers can complete a task in 12 days, how many days will 8 workers take to complete the same task? easy 2 marks Direct/Inverse Proportion
- 15 The intensity of light I at a distance d from a source follows an inverse proportionality. If I=400, W/m^2 at d=2,m, what is I at d=5,m? medium MCQ 3 marks Inverse Proportion
- 16 A group of 12 workers can build a wall in 15 days working 8 hours per day. How many days will 18 workers take to build the same wall if they work 6 hours per day? hard 5 marks Inverse Proportion (workers, hours, days)
- 17 Two cars travel the same distance. The ratio of their distances is 3:2 and the ratio of their speeds is 5:4. What is the ratio of the times taken by the two cars to travel that distance? hard 4 marks Inverse Proportion (time vs. speed)
- 18 If 6 pens cost Rs. 30, how many pens can be bought for Rs. 50? easy MCQ 1 mark Direct proportion of cost to quantity
- 19 If 4 workers can complete a house in 12 days working 6 hours per day, how many days will 6 workers take to complete the same house working 8 hours per day? medium 2 marks Inverse proportion with workers and hours
- 20 In a factory, the output of a machine is directly proportional to the number of hours it runs and inversely proportional to the amount of energy consumption per hour. If the machine runs for 5 hours with 3 kWh per hour and produces 150 units, how many units will it produce if it runs for 8 hours with 2 kWh per hour? hard 4 marks Combined direct and inverse proportion
- 21 A group of 5 students can read a 400-page book in 8 days, working 4 hours per day. How many days will 10 students, working 5 hours per day, take to read the same book? hard 4 marks Inverse proportion with workers, hours, and time