When they meet the red train will have been travelling for 2 hrs and 35 minutes less than the blue train.
If B is the time traveled by the blue train and, the the time traveled by the red train is B - (155/60)
(Note 35B is the distance traveled by the blue train & the other term is the distance traveled by the red train)
510B = 3000 + 775 = 3775
B = 7.401961; the red train's time is 4.818628
The blue train will ravel 259 miles the red train 259 miles