Direct and Inverse Proportions, Chapter 13 Class 8 Maths MCQs

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

(a) x – y = constant

(b) x + y = constant

(c) x × y = constant

(d)

2. If ‘x’ and ‘y’ are in an inverse variation then which of the following is correct?

(a) x – y = constant

(b) x + y = constant

(c) xy = constant

(d)

3. If ‘A’ can finish a work in ‘n’ days then part of work finished in 1 day is:

(a) 1 – n

(b) (c) n – 1

(d) none of these

4. If amount of work completed by ‘A’ in one day is then the whole work will be finished by ‘A’ is:

(a) n days

(b) 1 – n days

(c) n – 1 days

(d) none of these

5. If an increase in one quantity brings about a corresponding decrease in the other and ice versa, then the two quantities vary:

(a) directly

(b) inversely

(c) sometimes directly and sometimes inversely

(d) none of these.

6. “If speed is more than time to cover a fixed distance would be less”. This is a ease of:

(a) inverse variation

(b) direct variation

(c) direct variation

(d) none of the above

7. Which of the following is not a case of direct variation?

(a) Number of sheets of some kind are increased when their total weight its increased

(b) More quantity of petrol is required to travel more distance with a fixed speed

(c) More fees would be collected if number of students increased in a class

(d) Time taken will be less if number of workers are increased to complete the same work

8. Which of the following is ease of direct variation;

(a) If the length of radius is increased the circumference will be increased

(b) If number of students is a hostel are increased then the fixed food provision will last for less days

(c) For fixed duration, more the periods, lesser will be the duration of one period

(d) In case of a cylindrical vessel, lesser the diameter more is the level of water in it.

9. A garrison of 300 men had provision of food for 50 days. A reinforcement of 200 men arrived. Find the number of days for which the food will last.

a. 30

b. 20

c. 40

d. None of these

10. If 36 men can complete a work in 24 days, how many extra men be employed so as to complete the work in 18 days?

a. 24

b. 6

c. None of these

d. 12

11. 72 books are packed in 4 cartons of the same size. How many cartons are required for 360 books?

a. 20

b. None of these

c. 22

d. 18

12. When one quantity is increased, the other quantity is also increased. This proportion is called .....................

a. None of these

b. Inverse proportion

c. Kally proportion

d. Direct proportion

13. 25 labourers can build a wall in 4 days. IF only 20 labourers report for work, the wall be built in

a. 3 days

b. 6 days

c. None of these

d. 5 days

14. A car is traveling at a speed of 54 km/ hour, covers a distance in 2.5 hours. At a speed of 45 km/hr, it covers the same distance in

a. None of these

b. 1 hour

c. 3 hours

d. 2 hours

15. Raju earns Rs 1440, if he works for 12 days. If he works for 30 days, he will earn

a. Rs 2400

b. None of these

c. Rs 3600

d. Rs 4800