The area of cultivated land and the crop harvested is a case of direct proportion.

The number of workers and the time to complete a job is a case of direct proportion.

For fixed time period and rate of interest, the simple interest is directly proportional to the principal.

Which of the following vary directly and which vary inversely with each other and which are neither of the two?

(i) The time taken by a train to cover a fixed distance and the speed of the train.

(ii) The distance travelled by CNG bus and the amount of CNG used.

(iii) The number of people working and the time to complete a given work.

(iv) Income tax and the income.

(v) Distance travelled by an auto-rickshaw and time taken.

Which of the following vary directly and which vary inversely with each other and which are neither of the two?

(i) Number of students in a hostel and consumption of food.

(ii) Area of the walls of a room and the cost of white washing the walls.

(iii) The number of people working and the quantity of work.

(iv) Simple interest on a given sum and the rate of interest.

(v) Compound interest on a given sum and the sum invested.