In which of the following situational, does the list of numbers involved make an arithmetic progression, and why?
The amount of air present in a cylinder when a vacuum pump removes
of the air remaining in the cylinder at a time.
Amount of air present in the cylinder = x units (say) = a1
Amount of air present in the cylinder after one time removal of air by the vacuum pump![]()
Amount of air present in the cylinder after two times removal of air by the vacuum pump
and so on,![]()
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As a3 – a7 ≠ a3 – a2, this list of numbers does not form an A .P.



