CBSE Class 8 Maths Proportional Reasoning 2 (Class 8 NCERT New) Quiz 3

1. If 5 workers can move 4500 bricks in a day, how many workers are needed to move 18000 bricks in a day?

A 20 B 15 C 18 D 25

2. Puneeth’s father went from Lucknow to Kanpur in 3 hours by riding his motorcycle at a speed of 30 km/h. If he takes a car instead and drives at 60 km/h, how long will it take him to reach Kanpur (assuming the same distance)?

A 1.5 hours B 3 hours C 2 hours D 1 hour

3. Consider the proportionality statement 30 : 60 :: 3 : x for travel from Lucknow to Kanpur, where speeds are 30 km/h and 60 km/h and 3 hours is the travel time at 30 km/h. Which option correctly completes the statement and describes how travel time changes with speed?

A x = 1.5 and travel time decreases as speed increases. B x = 6 and travel time increases as speed increases. C x = 1.5 and travel time increases as speed increases. D x = 6 and travel time decreases as speed increases.

4. Going by bicycle is 3 times faster than walking (15 km/h compared to 5 km/h). Does the travel time for the same distance decrease by the same factor?

A Yes. The time decreases 3 times (from 18 hours to 6 hours). B No. The time decreases by 4 times. C Yes, but only if distance also changes. D No. The time remains the same.

5. Using the table of speeds and times for travelling the same distance of 90 km — Walk: 5 km/h and 18 h; Bicycle: 15 km/h and 6 h; Motorcycle: 30 km/h and 3 h; Car: 60 km/h and 1.5 h — do speed and time vary in inverse proportion across these modes?

A Yes. The product of speed and time is the same for all modes. B No. The product of speed and time varies across modes. C Yes, but only when the speed is less than 30 km/h. D No. They vary directly with each other.

6. Let x represent speed and y represent travel time for a fixed distance. For walking and by car, take x1 = 5, x2 = 60, y1 = 18 and y2 = 1.5. What is the value of (1/18) × (y2 / y1)?

A 0.083333... B 0.75 C 0.5 D 0.033333...

7. Which of these data sets show x and y in inverse proportion? Use each table to decide whether the product x × y stays constant across all pairs. (i) x: 40, 80, 25, 16; y: 20, 10, 32, 50 (ii) x: 40, 80, 25, 16; y: 20, 10, 12.5, 8 (iii) x: 30, 90, 150, 10; y: 15, 5, 3, 45

A Only (i) B Only (ii) C Only (iii) D (i) and (iii) 5 (ii) and (iii)

8. If x and y are in inverse proportion, use the pair (x, y) = (16, 9) to fill the missing values in the table: when x = 12, what is y?

A 6 B 9 C 12 D 18

9. If x and y are in inverse proportion, use the pair (x, y) = (16, 9) to fill the missing values in the table: when y = 48, what is x?

A 2 B 3 C 6 D 8

10. Which of the following pairs of quantities are in inverse proportion? Select all that apply. (i) The number of taps filling a water tank and the time taken to fill it (ii) The number of painters hired and the days needed to paint a wall of fixed size (iii) The distance a car can travel and the amount of petrol in the tank (iv) The speed of a cyclist and the time taken to cover a fixed route (v) The length of cloth bought and the price paid at a fixed rate per metre (vi) The number of pages in a book and the time required to read it at a fixed reading speed

A (i), (ii), and (iv) B (i) and (ii) only C (iii) and (v) only D (iv) and (vi) only 5 (ii), (v), and (vi)