(i) These are in inverse proportion because if there are more workers, then it will take lesser time to complete that job.
(ii) No, these are not in inverse proportion because in more time, we may cover more distance with a uniform speed.
(iii) No, these are not in inverse proportion because in more area, more quantity of crop may be harvested.
(iv) These are in inverse proportion because with more speed, we may complete a certain distance in a lesser time.
(v) These are in inverse proportion because if the population is increasing, then the area of the land per person will be decreasing accordingly.