Ravi runs at a speed of 45 m/min. After 6 minutes, Siva starts chasing Ravi at a speed of 60 m/min. A dog starts running along with Siva at a speed of 80 m/min. If the dog reaches Ravi and comes back to Siva, and goes back to Ravi, and so on and so forth, until Siva meets Ravi, then find the total distance covered by the dog in metres.