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Class 8

Explore popular questions from Direct and Inverse Proportions for Class 8. This collection covers Direct and Inverse Proportions previous year Class 8 questions hand picked by experienced teachers.

Direct and Inverse Proportions

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Q 1. If 'x' and 'y' are in a direct proportion then which of the following is correct?

A

{tex}x - y{/tex} = constant

B

{tex}x + y{/tex} = constant

C

{tex}x \times y{/tex} = constant

{tex}\frac{x}{y}{/tex} = constant

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Q 2. If the amount of work completed by 'A' in one day is {tex}\frac{1}{n}{/tex} then the whole work will be finished by 'A' is :

n days

B

1 - n days

C

n - 1 days

D

none of these

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Q 3. "If speed is more that time to cover a fixed distance would be less". This is a case or :

inverse variation

B

direct variation

C

direct and indirect both variations

D

none of the above

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Q 4. If x and y vary inversely. Then using the following table?

x {tex}\quad{/tex} 5 {tex}\quad{/tex}
y 30
The value of x for y = 10 is

A

10

B

40

15

D

20

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Q 5. The ratio of girls to boys in a class is 2 : 3. The actual strength of the class is :

A

12

15

C

16

D

18

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Q 6. If two quantities x and y are related to each other in such a way that {tex}\frac{x}{y}{/tex} remains a positive constant, then x and y are said to be in

A

inverse variation

direct variation

C

variation

D

none of these

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Q 7. The cost price of articles and number of articles are said to be in

direct variation

B

inverse variation

C

variation

D

none of these

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Q 8. Time taken to cover a distance by a car and speed of the car are said to be in

A

direct variation

inverse variation

C

variation

D

none of these

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Q 9. If 12 m of a uniform iron rod weights 42 kg, what will be the weight of 6 m of the same rod?

A

20 kg

21 kg

C

84 kg

D

42 kg

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Q 10. A certain number of men can finish a piece of work in 100 days. If however, there were 10 men to be finished. How many men were originally there?

A

90

B

100

110

D

120

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Q 11. If 20 binders bind 1000 books in 10 days, then how many books will binded by 10 binders in 20 days?

A

2000

1000

C

1500

D

900

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Q 12. A train 150 m long, is running at a speed of 90 km/hr. Then time taken by the train to cross a tree is

A

3 sec

B

4 sec

C

5 sec

6 sec

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Q 13. x and y are in inverse proportion. If y = 15 when x = 3, then value of y when x = 9, is

A

45

5

C

8

D

9

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Q 14. x and y are in direct variation. If y = 10 when x = 5, then value of y when x = 10, is

A

2

B

5

C

10

20

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Q 15. 15 books weight 6 kg. What will 6 books weight?

A

1.2 kg

2.4 kg

C

3.8 kg

D

3 kg

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Q 16. 8 g of sandal wood cost Rs.40. What will 10 g cost ?

A

Rs.30

B

Rs.36

C

Rs.48

Rs.50

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Q 17. 20 trucks can hold 150 metric tonnes. How much will 12 trucks hold?

A

80 metric tonnes

90 metric tonnes

C

60 metric tonnes

D

40 metric tonnes

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Q 18. A boy runs 1 km in 10 minutes. How long will he take to run 600 m?

A

2 minutes

B

3 minutes

C

4 minutes

6 minutes

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Q 19. A shot travels 90m in 1 second. How long will it take to go to 225 m?

A

2 seconds

2.5 seconds

C

4 seconds

D

3.5 seconds

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Q 20. The fare for a journey of 40 km is Rs.25. How much can be traveled for Rs.40?

A

32 km

64 km

C

50 km

D

60 km

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Q 21. A machine in a soft drink factory fills 600 bottles in 5 hours. How many bottles will it fill in 2 hours?

A

120

B

180

C

150

240

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Q 22. 10 men can dig a trench in 15 days. How long will 3 men take?

50 days

B

60 days

C

100 days

D

75 days

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Q 23. 6 pipes are required to fill a tank in 1 hour. How long will it take if only 5 pipes of the same type are used?

A

75 minutes

72 minutes

C

80 minutes

D

90 minutes.

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Q 24. 40 cows can graze a field in 16 days. How many cows will graze the same field in 10 days?

A

60

64

C

80

D

75