While asking these sort of agile testing interview questions, employers try to recognize if you really understand the benefits of this methodology and can see a practical application of it in various areas of business. To state that this methodology can be, and maybe even should be, applied in all the instances and test cases where we have insufficient entry data, or work in an unknown area, or simply work within a small team, or where many unpredictable variables take place is a good answer. It is in fact used quite commonly in bio-medicine, biochemistry or physics. Anyway, it could be used in many other areas.