Question

Is the series 1, 4,… to n terms an A.P., or a GP, or an HP, or a series which cannot be determined?

Answer 1

To determine any progression, we should have at least three terms. 

If the series is an A.P. then the next term of this series will be 7 Again, 

if the next term is 16, then this will be a GP series (1, 4, 16 …) 

So, we cannot determine the nature of the progression of this series.