Given: The probability that it will rain today = 0.55 Concept used: 1.) The probability of an event will not be less than 0 because 0 is impossible (sure that something will not happen). 2.) The probability of an event will not be more than 1. This is because 1 is certain that something will happen. 3.) The probability of an event is always between 0 to 1 Calculations: The probability that it will not rain today = 1 – 0.55 ⇒ 0.45 = 9/20 ∴ The probability that it will not rain today is 9/20