In which of the following situations,does the list of numbers involved make an arithmetic progression,and why?(ii)The amount of air present in a cylinder when a vacuum pump remove 1/4 of the air remaining in the cylinder at a time .

In which of the following situations,does the list of numbers involved make an arithmetic progression,and why?(i) The taxi fare after each km when the fare is Rs 15 for the first km and Rs 8 for each additional km.

In which of the following situations,does the list of numbers involved make an arithmetic progression,and why?(iii) The cost of digging a well after every metre of digging,when it cost Rs 150 for the first metre and rises by Rs 50 for each subsequent metre.