A group of tourists is traveling in outback Australia. They are planning to travel from Looloo to Pearl Rock via the towns of Mt Tedious, Nimboi Creek, and Ommata. The distances involved are Looloo to Mt Tedious is 71km, Mt Tedious to Nimboi Creek is 10km, Nimboi Creek to Ommata is 50km, and Ommata to Pearl Rock is 73km. The tourists' car has a fuel tank that will allow it to drive 100km before refueling. However, there is a fuel strike on and so there is a possibility that each of the towns might not have fuel.
If the tourists start at Looloo with a full tank of fuel and intend to refuel every chance they get, which of the following fault trees (1-8) most accurately describes the probability that they will get to Pearl Rock without being delayed by having to wait in one of the intermediate towns for the fuel strike to finish? (In the following diagram M means there is fuel at Mt Tedious, N means there is fuel at Nimboi Creek, and O means there is fuel at Ommata).
