Nylah has her living room lights on a timer. Each evening, the timer switches the lights on randomly at exactly 7:00 p. m., 7:30 p. m., 8:00 p. m., 8:30 p. m., or 9:00.p. m. Later in the evening, the timer switches the lights off at any random time between 11 p. m. and 1 a. m. For example, the lights could be switched on at exactly 7:30 p. m. and off at any one of the infinite number of possible times between 11 p. m. and 1 a. m. On a given night, Nylah's lights are on for t hours. What is the probability that 4<t<5?