A train starts from place A at 5 P.M. and reaches place B at 6 P.M. and another train starts from. place B at 5 P.M. and reaches place A at 6 : 30 P.M. The two trains will cross each other at

The correct answer is (c).

The two trains travel in opposite directions, so they will cross each other when they are at the same point on the track. The first train travels for 1 hour, and the second train travels for 30 minutes. Therefore, the two trains will cross each other at 5:45 P.M.

Option (a) is incorrect because the first train only travels for 1 hour, so it cannot reach place B at 6:30 P.M.

Option (b) is incorrect because the first train only travels for 1 hour, so it cannot reach place B at 5:48 P.M.

Option (d) is incorrect because the first train only travels for 1 hour, so it cannot reach place B at 5:36 P.M.