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.

Question

Philoid · Accepted Answer

1: The time taken by a train to cover a fixed distance and the speed of the train are inversely proportional.

E.g. If train cover 100km in 1h with speed 100km/h.

Then, the same train cover 100km in 1h with speed 200km/h.

2: The distance travelled by CNG bus and the amount of CNG used are directly proportional. E.g. if CNG bus can travel 10km in 1 kg of CNG.

Then, the same CNG bus can travel 20km in 2kg CNG.

3: The number of people working and the time to complete a

given work are inversely proportional to each other.

e.g. If 20 workers can complete a work in 1day.

Then, 10 workers can complete the same work in 2days.

4: Income tax and the income are directly proportional to each

other, e.g. If Mr.X have 4.5 lakh annual income.

Then, he pays 10% income tax on his income

But if Mr.X have 5.5 lakh annual income, then he has to pay 30% income tax on his income.

5: Distance travelled by an auto rickshaw and time taken are directly proportional to each other.

e.g. If an auto rickshaw takes 2h travel 10km

Then, it will take 4h to travel 20km.