Answer:
P = 1/2
Step-by-step explanation:
If the tourist spends more than 275$, they must not arrive in Chicago by bus.
( 150 + 60 < 275, 150 + 40 < 275)
The total options the tourist can make:
3 x 2 = 6
(1st leg: 3 possible options, 2nd leg: 2 possible options)
The number of options the tourist can make after excluding bus option:
2 x 2 = 4
(1st leg: 2 remaining possible options, 2nd leg: 2 possible options)
The number of options the tourist can make after excluding the bus option and spend more than 275$:
4 - 1 = 3
(excluding the case of selecting train and cab, because 225 + 40 < 275)
=> The probability that the tourist will spend more than 275$ on these 2 legs of the trip:
P = 3/6 = 1/2