Question

Which of the following quantities vary directly with each other?
a) speed and time (distance covered remaining the same)
b) area of land and its cost
c) number of men required for a job and time taken to finish the job
d) number of persons and days needed by them for consumption of food (amount
of food remaining the same)

Answer 1

a) speed and time (distance covered remaining the same)

Answer 2

area of land and its cost because when puchasing of land increase the cost will also increase