In which of the following situations, does the list of numbers involved make an 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 by Rs. 50 for each subsequent metre.

Question

Philoid · Accepted Answer

Given that cost for digging 1^st meter is Rs. 150 so that is first term ‘a’ of the series.

And also we have been given that for every meter after 1^st meter digging is Rs. 50

So, for 2 meter it will be 150 + 50 = 200

Similarly, 3 meter = 150 + 50 + 50 = 250

In the same way it adds on for every another meter digging

If we put cost of digging in series for each meter. It will look like this,

150, 200, 250, 300, ……

On seeing the above series we can conclude that it is in A.P.

∵ They have same common difference between two consequent numbers (d = 50).

In which of the following situations, does the list of numbers involved make an 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 by Rs. 50 for each subsequent metre.