How many unknown person sits in the table?

G sits third to the left of W, who sits sixth to the right of E. Only one person sits between E and D. G is not an immediate neighbour of D.F is an immediate neighbour of E There are seven person sits between Y and F when counted from the left of F. Only two people sits between W and Y. Y sits immediate right of X. Number of person sits between C and Y when counted from the right of Y is equal to the number of persons sits between O and F when counted from the left of F. No known person sits near to C. Z sits third to the right of X. From this statement we cannot fix the position of C in case 2. So this case is eliminated.