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.
(ii) The amount of air present in a cylinder when a vacuum pump removes 1/4 of the air remaining in the cylinder at a time.
(iii) The cost of digging a well after every metre of digging, when it costs Rs.150 for the first metre and rises by Rs. 50 for each subsequent metre.
(iv) The amount of money in the account every year, when ` 10000 is deposited at compound interest at 8 % per annum.

Explanation

To determine whether the given situations form an arithmetic progression (AP), we need to analyze each scenario step by step.

### Solution:

**(i) Taxi fare after each km:**
- Fare for the first km = Rs 15
- Fare for the second km = Rs 15 + Rs 8 = Rs 23
- Fare for the third km = Rs 23 + Rs 8 = Rs 31
...