Symbiosis National Aptitude Test SNAP 2013 Paper

Total no. of seats = 1 grand-father + 5 sons and daughters + 8 grand-children
The grand-children can occupy the 4 seats on either side of the table in 4 ! = 24 ways
The grand-father can occupy a seat in (5 – 1) = 4 ways (4 gaps between 5 sons and daughters)
And the remaining seat can be occupied in
5! = 5 × 4 × 3 × 2 = 120 ways
(5 seat for sons and daughters)
Hence, the total number of required ways = 8 ! × 480 = 193536