what is true about the probabilty of an event and its complement?

 

   what is true about the probabilty of an event and its complement?     

 

   There are a lot of truths about probability and its complement.     

   I think maybe the one you mean is that they always sum to 1.     

 

   When there's a probability that an particular event will occur,     

   its complement is the probability that the event will not occur.     

 

   For example, the probability that you will roll a 4 on a die is 1 / 6.     

   Then, the complement that you will not roll a 4 on the die is 5 / 6.     

   _.