# Direct and Inverse Proportions – Class 8 / MCQ

**CBSE CLASS 8 MATHEMATICS**

**Direct and Inverse Proportions: Chapter 13/MCQ**

**Multiple Choice Questions**

**Choose the correct answers from the options given below:**

**1. Two quantities x and y are said to be in ————- proportion if they increase (decrease) together in such a manner that the ratio of their corresponding values remains constant.**

A. Direct Proportion

B. Inverse Proportion

C. Equal Proportion

**2. Two quantities x and y are said to be in ————- if an increase in x causes a proportional decrease in y and vice-versa in such a manner that the product of their corresponding values remains constant.**

A. Direct Proportion

B. Inverse Proportion

C. Equal Proportion

**3. x and y are said to vary directly if —————**

A. xy = k, k is a positive number.

B. x/y = k, k is a positive number.

C. x + y = k, k is a positive number.

**4. x and y are said to vary inversely if ————–**–

A. xy = k, k is a constant.

B. x/y = k, k is a constant.

C. x + y = k, k is a constant.

**5. More the money deposited in a bank more is the interest earned. This is a case of ———————**–

A. Direct proportion

B. Inverse proportion

C. Equal proportion

**6. For a given job, more the number of workers, less will be the time taken to complete the work. This is a case of ———-**

A. Direct Proportion

B. Inverse proportion

C. Equal proportion

**7. Which of the following are in inverse proportion?**

A. The population of a country and the area of land per person.

B. Area of cultivated land and the crop harvested.

C. The time taken for a journey and the distance traveled in a uniform speed.

**8. If 15 workers can build a wall in 48 hours how many workers will be required to do the same work in 30 hours?**

A. 20

B. 22

C. 24

**9. A train is moving at a uniform speed of 75 km/hour. How far will it travel in 20 minutes?**

A. 15 km

B. 20 km

C. 25 km

**10. If the cost of 1 kg of sugar is Rs 36, then what would be the cost of 3 kg sugar?**

A. 12

B. 39

C. 108

**ANSWERS:**

**1. Direct proportion**

**2. Inverse proportion**

**3. x/y = k, k is a positive number.**

**4. xy = k, k is a constant.**

**5. Direct proportion**

**6. Inverse proportion**

**7. The population of a country and the area of land per person.**

**8. 24**

**(Let the number of workers employed to build the wall in 30 hours be y.**

**This is a case of Inverse proportion.**

**So 48 x 15 = 30 x y**

**Therefore, y = 48 x 15/30 = 24)**

**9. 25 km**

**(Let the distance (in km) in 20 minutes be x and time taken (in minutes) to cover 250 km be x. This is a case of direct proportion.**

**So x = 75 x 20/60 = 25 km)**

**10. 108 rupees.**