Final answer:
To find the next day on which Dillion, William, and Francis will all work together, we need to find the least common multiple (LCM) of their work schedules. The LCM of 3, 4, and 5 is 60. Therefore, they will next work together on Saturday.
Step-by-step explanation:
To find the next day on which Dillion, William, and Francis will all work together, we need to find the least common multiple (LCM) of their work schedules. Dillion works every third day, William works every fourth day, and Francis works every fifth day. The LCM of 3, 4, and 5 is 60. Since they all worked together on Thursday, we can count forward 60 days to find the next day they will work together, which is 60 days after Thursday. Therefore, they will next work together on Saturday.