The number of persons sits between R and S is the same

Solution

STEP I: M sits third to the left of O who sits an immediate neighbour of S. Three persons sit between Q and S who sits second to the left of N. As per these statements, we can say that there are three possible cases and the arrangement will look like this: STEP II: R sits to the immediate left of P who sits second to the left of M. Both R and Q sit adjacent to each other. The number of persons sits between P and S is one less than the number of persons sits between S and R when counted from the right of both P and S respectively. At least one person sits between N and R when counted from the right of N. As per these statements, CASE I and CASE III get eliminated and we continue with CASE II and the final arrangement will look like this: