Is this question of sequence a Mathematical one, i.e. does it have objectively only one answer for each subpart. This question is taken from 11th class Math book. Look at this question:   

At the very first glance one can tell that all the three sequences are G.P But! by using interpolation(as this answer explains) we can give any number of answers to (a),(b) and (c).   

  
*
  
*Is the above mentioned question technically, a mathematical question ?   
  

The above mentioned question is taken from NCERT, Mathematics textbook for Class XI, chapter-9 Exercise 9.3, 5th question.     
Can we use interpolation to solve this question on sequences? The book mentions only one correct answer for 5th question. If The question-5 that I quoted in the question above can also be answered by interpolation then this way the book will be technically incorrect; which is less likely to be because it is a standard book.

So, is the book technically incorrect?


I've already answered the actual question in my comments, but I'd like to answer the question in the textbook. I think (b) and (c) are not geometric progressions. In each case, just multiply the previous two to get the next one.
In case you didn't realize, I'm joking. =)
