Try this problem from I.S.I. B.Stat Entrance Objective Problem based on Arrangement in a Ring.
The number of ways 5 persons PQRST seats in a ring so that P sits between Q and R is
But try the problem first...
B.Stat Objective Problem 103
Challenges and Thrills of Pre-College Mathematics by University Press
here SQPRT, TQPRS, SRPQT, TRPQS
are 4 arrangements in 1 way (orderwise)
number of ways =\(4 \times 1\)=4 ways.