Complete the following statements:
(i) Probability of an event E + Probability of the event ‘not E’ = ________.
(ii) The probability of an event that cannot happen is ________. Such an event is called ________.
(iii) The probability of an event that is certain to happen is ________. Such an event is called ________.
(iv) The sum of the probabilities of all the elementary events of an experiment is ________.
(v) The probability of an event is greater than or equal to ________ and less than or equal to ________.
(i) 1
(ii) 0; impossible event
(iii) 1; sure or certain event
(iv) 1
(v) 0, 1
The probability of the complement of an event is 1 minus the probability of the event itself, so their sum is 1. An event that cannot occur has probability 0 and is called an impossible event, while an event that is sure to occur has probability 1 and is called a certain (sure) event. The probabilities of all elementary outcomes in a sample space add up to 1, and probabilities of any event always lie between 0 and 1 inclusive.