After we examine the rules and combine them. We find that there are two options for the order between J, P, and L.
J - P - L or L - P - J
As for the rest of the sequence.
T is before M which is before L
T is also before N and P, which are directly adjacent to each other.
This means that M, L, N, and P must always come after the teachers at a minimum. And it is possible for J but not necessary. This is why the answer is four.
I hope this helps. Please let me know if you have any other questions.
