GATE2017 CE-2: GA-8

Question

$P, Q, R, S, T$, and $U$ are seated around a circular table $R$ is seated two places to the right of $Q. \: P$ is seated three places to the left of $R. \: S$ is seated opposite $U.$ If $P$ and $U$ now switch seats, which of the following must necessarily be true?

• A. $P$ is immediately to the right of $R$
• B. $T$ is immediately to the left of $P$
• C. $T$ is immediately to the left of $P$ or $P$ is immediately to the right of $Q$
• D. $U$ is immediately to the right of $R$ or $P$ is immediately to the left of $T$

Answer 1

$P\;Q\;\_ \;R$

Since $S$ is seated opposite of $U$ it means on its left and right side there must be $2$ members. So, only option is to be seated to the left of $P$ and right of $Q$. This leaves the space to the immediate right of $R$ for $T.$

$P\;Q\;\_ \;R\;T\; \_$

Now, $P$ and $U$ switch the seats:

$U\;Q\;\_ \;R\;T\; \_$

The gaps are taken by $P$ and $S$ but their exact positions are unknown

Now seeing the options:

• (A) is false as $T$ is immediately to the right of $R$
• (B) may of may not be true as we have two choices for $P$
• (C) is TRUE
• (D) is false as $T$ is immediately to the right of $R$ and $R$ is immediately to the left of $T$

Correct answer: C

Answer 2

Correct Answer: $C.$ T is immediately to the left of P or P is immediately to the right of Q

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there are two possible initial cases:

Case 1:

after switching P and U's position

here, T is immediately to the left of P

Case 2:

after switching P and U's position

here, P is immediately to the right of Q