Five plays K, L, M, N and O are to be staged on five consecutive days from Monday to Friday. On each day only one play is staged. N or O cannot be either the first play staged on Monday or the last play staged on Friday. Play O must be staged immediately before play M. Play L must be staged immediately after play N. There is exactly one play staged between K and L. Under these conditions, which play is the second play to be staged in the weekly schedule?

Introduction / Context:
This logical sequencing question involves scheduling five different plays over five days of the week. The plays must follow a set of constraints about their relative positions. The aim is to determine which play will be staged second, not to write the entire timetable directly. This type of puzzle tests the ability to translate verbal conditions into positional relationships and systematically deduce a unique arrangement.

Given Data / Assumptions:

• Five plays: K, L, M, N, O are to be staged from Monday to Friday.
• Only one play is staged per day, and each play is staged exactly once.
• N or O cannot be on the first or the last day.
• O is immediately followed by M, so the pair O M appears consecutively in that order.
• L is immediately after N, so the pair N L appears consecutively in that order.
• Exactly one play is staged between K and L.

Concept / Approach:
We treat the days as five slots from 1 to 5. The constraints form chains: O M and N L are fixed pairs. Since N and O cannot be first or last, we must consider possible positions for these pairs, then place K such that there is exactly one play between K and L. Finally, we verify which complete arrangement satisfies all the conditions simultaneously, and from that arrangement we read off the second play.

Step-by-Step Solution:
Step 1: Because O must be followed by M, O M can occupy slots (1,2), (2,3), (3,4), or (4,5). But N and O cannot be first or last, which already restricts placement.Step 2: N must be immediately followed by L, so N L can occupy slots (1,2), (2,3), (3,4), or (4,5), but N also cannot be first or last.Step 3: Try constructing a valid schedule. A consistent arrangement that satisfies all constraints is K N L O M from Monday to Friday.Step 4: Check this arrangement: N and O are not first or last. O is directly before M. L follows N immediately. There is exactly one play (L) between K and L, since K is day 1 and L is day 3.Step 5: No alternative arrangement accommodates all conditions without contradiction, so K N L O M is the unique valid ordering.

Verification / Alternative check:
We can confirm uniqueness by trying to shift the pairs. If N L starts at day 1, N would be first, which is forbidden. If it starts at day 4, L would be last, forcing O M earlier and failing the single gap constraint with K. Testing other positions leads to conflicts with the adjacency and not-first-not-last restrictions, confirming K N L O M is the only consistent schedule.

Why Other Options Are Wrong:
Option A (L) would require L to be in second position, but L must come immediately after N, so N would then need to be first, which is not allowed. Option B (O) would push the O M pair too early and break other constraints. Option C (M) would mean O is first, again violating the rule. Only option D, N, fits the valid schedule derived from all constraints.

Common Pitfalls:
Many learners try to assign days randomly to plays without tracking all constraints simultaneously, leading to partial arrangements that seem correct but fail one hidden rule. Another frequent mistake is to forget that N and O are both barred from the first and last days. Drawing a simple table with slots 1 to 5 and writing the pairs consecutively is an effective way to avoid such errors.

Final Answer:
In the only valid arrangement K N L O M, the second play to be staged is N.