Experiment X involves unlocking of bombs. Several police officers are trained in this experiment. Artificial bombs and keys for unlocking these bombs were created and the setting is done such that if the officer inserts a wrong key in a bomb, an explosion occurs outside a training building. Provide the probability of an explosion to occur if there is/are:

a)one bomb and a bunch of two keys, such that only one key can unlock the bomb.

b)Two bombs of different designs and one key of the same design with one of these bombs, such that design is a direct indication of unlocking these bombs.

c)Two bombs of the same structural design and a key, such that this key can unlock one of them.

d) Two bombs of the same structural design and a bunch of two keys, such that each key can unlock one of them.

e)Two bombs of the same structural design and a bunch of three keys, such that only two of these keys each can unlock one of them.