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

In which of the following situations, does the list of numbers involved make arithmetic progression, and why ? The taxi fare after each km when 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 arithmetic progression, and why ? The amount of money in the account every year, when Rs.10,000 is deposited at compound interest at 8% per annum.

In which of the following situations, does the list of numbers involved make arithmetic progression, and why ? 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.

There is a square field whose side is 44 m. A square flower bed is prepared in its centre leaving gravel path all round the flower bed. The total cost of laying the flower bed and gravelling the path of Rs. 2.75 and Rs. 1.50 per metre square respectively is Rs. 4904 . Find the width of the gravel path.

A mansion has 12 right cylindrical pillars each having radius 50cm and height 3.5m. Find the cost to paint the lateral surface of the pillars at Rs.20 per square metre.