UPSC Prelims 2026 CSAT, question 14

Topic: Arrangements and puzzles

Q14

Eight persons $P,Q,R,S,T,U,V$ and $W$ sit around a round table in eight different seats placed with equal distance between any two consecutive seats. Both $P$ and $R$ are adjacent to $Q$ . Both $T$ and $R$ are adjacent to $S$ . Both $U$ and $W$ are adjacent to $V$ . $S$ and $W$ are on opposite chairs. If while going in the clockwise direction around the table from $P$ , one meets $R$ before $T$ , then how many persons shall $Q$ cross while moving in the clockwise direction around the table before meeting $W$ ?

(a) 5Correct answer
(b) 4
(c) 2
(d) 1

Solution.

Answer: (a) 5

Since $P$ and $R$ are adjacent to $Q$ , and $T$ and $R$ are adjacent to $S$ , the five persons $P, Q, R, S, T$ sit consecutively in that order; going clockwise from $P$ meets $R$ before $T$ , so their clockwise order is $P, Q, R, S, T$ at seats $0, 1, 2, 3, 4$ .
Because $S$ (seat $3$ ) and $W$ are opposite on the 8-seat circle, $W$ is at seat $7$ ; since $U$ and $W$ are adjacent to $V$ , $V$ is at seat $6$ and $U$ is at seat $5$ .
Moving clockwise from $Q$ (seat $1$ ) to $W$ (seat $7$ ) passes seats $2, 3, 4, 5,$ and $6$ ( $R, S, T, U, V$ ), so $Q$ crosses $5$ persons.