List all the different combinations with total cost:
Airplane + van = 350 + 60 = $410
Airplane + cab = 350 + 40 = $390
Bus + van = 150 + 60 = $210
Bus + cab = 150 + 40 = $190
Train + van = 225 + 60 = $285
Train + cab = 225 + 40 = $265
There are 6 different combinations.
There are 2 that are more than $300
The probability would be quantity higher than 300 / total combinations.
Probability = 2/6 = 1/3