Applied Course | Mock GATE | Test 1 | Question: 38

Question

Five cities P, Q, R, S, T are connected by different modes of transport as follows:

• P and Q connected by boat as well as rail.
• S and R connected by bus and boat.
• Q and  T connected by air only.
• P and  R connected by boat only.
• T and R connected by rail and bus.

If a person visits each of the places starting from P and gets back to P which of the following places must he visit twice?

• A. P
• B. Q
• C. R
• D. T

Answer 1

From the information given, we find that the cities P, Q, R, S, T  are connected as follows:
$\begin{array}{lcr} P \Leftarrow & \Rightarrow R \Leftarrow & \Rightarrow S \\ \Uparrow & \Uparrow  & \\ \Downarrow & \Downarrow & \\ Q \Leftarrow & \Rightarrow T & \end{array}$
To go to S back to P, R must be visited twice.