The most efficient way to solve this problem is to first find the total distance covered by both people combined, and then use the ratio of their speeds to find Rohit's individual distance.

1. Calculate the Total Distance Covered by Both People:
   • For the first meeting, they start at opposite ends and walk towards each other. They collectively cover the width of the room one time: 30 m.
   • For every subsequent meeting (the second, third, etc.), they must each hit an opposite wall and turn back. This means that for each additional meeting, they collectively cover the width of the room twice.
   • Distance covered between 1st and 2nd meeting = 2 * 30 = 60 m.
   • Distance covered between 2nd and 3rd meeting = 2 * 30 = 60 m.

   Therefore, the total distance covered by both until the third meeting is: 30 + 60 + 60 = 150 m.

2. Determine the Ratio of Distances Travelled:

   Since they walk for the same amount of time, the distance each person covers is directly proportional to their speed.

   Ratio of Speeds (Rohit : Tina) = 2 m/s : 1 m/s = 2 : 1

   This means for every 3 meters they cover combined, Rohit covers 2 meters. So, Rohit will always cover 2/3 of the total combined distance.

3. Calculate Rohit's Individual Distance:

   We take Rohit's share (2/3) of the total combined distance (150 m).

   Rohit's Distance = (2 / 3) * 150 m = 100 m

Final Answer: The total distance travelled by Rohit when he meets Tina for the third time is 100 m.