RT=D uniform travel rate rule relates rate, time, distance.
speed time distance
BUS 40 () ()
TRAIN 110 () ()
Total 210
You could either pick variables for each of the missing times or pick variables for each missing distance, but maybe you need more information.
speed time distance
BUS 40 () (x)
TRAIN 110 () (210-x)
Total 210
The choices listed are strange; You need more information.
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MAYBE you meant total time was 312 hours?