6 persons A, B, C, D, E and F are sitting in a row facing north (not necessarily in the same order). A is the immediate neighbour of D and F. F is the immediate neighbour of E and A. B is in the second position from the right end. If D is not at any of the ends, then how many persons are sitting towards the left of D? |
2 1 5 3 |
3 |
Answer: 3 In this question we will first place B second from the right end. There will be now two ways to place the others E F A D or D A F E, but we know D cannot sit at corner so now only one option is left. And C sits at the right end |