https://www.geeksforgeeks.org/computer-organization-risc-and-cisc/ check the comparison table.   [...]

I think in option B word "nation's" is mentioned which don't talk about India specifically. Nation can be any country.So according to me B is wrong option. then answer is D. [...]

The answer should be C) Bina. Here is a stepwise solution ->  1. China is sitting 3rd to the left of Dipa.(both facing inside) 2. Elina is not sitting adjacent to either of China or Dipa => only one position is left for her 3. One sitting between Dipa and Fiona will be facing outside => Dipa and Fiona need to have one empty place between them, this fixes the position of Fiona. 4. Gita sits 3rd to the right of Aina => it is not possible if we consider that Aina is facing inside(no empty place with a gap [...]

nth group starts with $(n-1)$$^{2}$ $+$ $1$ and ends with $n$$^{2}$ and every group consists $2n-1$ numbers $15th$ group starts with 196 and ends with $225$ $sum$ = $\frac{No of terms}{2}$ * $[first$ $term$+$last$ $term]$ = $\frac{29}{2} * [(196+1) + 225]$ = $6119$ [...]

acknowledge-Ignored [...]