Riddles, brain puzzles and mathematical problems

[Statyk]

Next question:

This crudely drawn circuit has 3 switches on top and 2 at bottom. The probability that any switch is open is 1/3.

Find the probability that a current can travel across this circuit.

The question does not state if switches are shut... Are we including these as possibly being closed switches?

If all switches are open... there is no circuit and 0% probability. So I may just have my points wrong here... 0% probability doesn't seem right.