Question

Which of the following are in inverse proportion?

• A. The number of workers on a job and the time to complete the job.
• B. The time taken for a journey and the distance travelled in a uniform speed.
• C. Area of cultivated land and the crop harvested.
• D. The time taken for a fixed journey and the speed of the vehicle.
• E. The population of a country and the area of land per person.

Answer 1

Answer: (A), (D), (E)

The number of workers on a job and the time to complete the job.
The time taken for a fixed journey and the speed of the vehicle.
The population of a country and the area of land per person.

Inverse proportion is a relation between two quantities such that one increases in proportion as the other decreases i.e. If $x$ increases as $y$ decreases, $x\alpha \frac{1}{y}$

In option A, if the no. of workers are increased then the time required to do the job will decrease, likewise if no. of workers decrease, then time to do the same job will increase i.e. no. of workers and time to do the job are inversely proportional to each other.

Similarly is the option D and E where the time taken to complete the journey is inversely proportional to the speed of vehicle and population is inversely proportional to area of the land respectively, are both examples of inverse proportion.

So, the answer is A, D, E.