A math conference is presenting a lecture series with six different lecturers. If Dr. Smith's lecture depends on Dr. Jones's lecture, so that Dr. Smith must be scheduled at some time after Dr. Jones, in how many orders can the six lecturers be scheduled?
I think basically, this is saying smith and jones must be next to each other
there are 5 ways to make that happen in 6 time slots
the other 4 time slots can be distributed 4! ways 5 x 4! = 120 ways