Question

Write the probability of a sure event.

Answer 1

The probability of a sure event is 1

i.e. P(S) = 1 where ‘S’ is the sure event. 

Proof: In a sure event n(E) = n(S)

[Since number of elements in Event 'E' will be equal to the number of element in sample space.] 

By definition of probability: 

`P(S) = (n(E))/(n(S)) = 1` 

P(S) = 1