A number is randomly selected from {80, 81, 82, 83, 84, 85, 86}.

A is represented by the event that the number picked is less than 84.

What is the probability of the complement of event A?

A. 27

B. 37

C. 47

D. 57

The probability that the number picked is less than 84 p (A) is:

number of possible events with picked number less than 84 / total number of possible events = 4/7

The complement event of A is that event A does not occur. If the picked number is not less than 84 (this means is greater than 84 or is 84). The probability of the complement event is:1 - p (A) = 3/7

Solution: B