Hello, I need some help with one math problem:

"There are TWO events, one of these events has probability 0,84. (nothing is said about other event ) What probability is to have 4 of 6 such events occured."

As I imagine these events should happen in pairs [0,84, ???], [0,84, ???] and [0,84, ???].

6 events, 3 probabilities unknown.

any ideas?