We know that the ad replays at a random time in each 3-hour interval and want to find the probability that Julio will see it while watching a 30-minute sitcom. We can use a number line to model this situation. Since the ad replays at a random time in each 3-hour interval, we know it will play in 3 hours or less from the start of the sitcom.
On our number line the event of Julio seeing the ad during the sitcom is represented by the segment AB. Let's use geometric probability. The probability of this event is the ratio of the length of AB and the length of AE.
