Arrange the following times in ascending (earliest-to-latest) order under the 24-hour clock: (a) 0640 hrs, (b) 1930 hrs, (c) 1335 hrs, (d) 2000 hrs.

Introduction / Context:
Time-ordering questions evaluate your facility with the 24-hour (HHMM) clock format. You must translate each time into chronological order without confusing morning and evening entries.

Given Data / Assumptions:

• Times: 0640, 1335, 1930, 2000 (all in hours-minutes, 24-hour format).
• Goal: ascending order (earliest → latest).

Concept / Approach:
24-hour times compare lexicographically by hour first, then by minutes when hours match. Convert informally: 0640 = 6:40 a.m., 1335 = 1:35 p.m., 1930 = 7:30 p.m., 2000 = 8:00 p.m.

Step-by-Step Solution:

Verification / Alternative check:
Compare numerically: 0640 < 1335 < 1930 < 2000, consistent with the constructed order.

Why Other Options Are Wrong:

• Any sequence not starting with 0640 or not ending with 2000 mis-orders the day.

Common Pitfalls:
Misreading 1335 as 3:35 p.m.; forgetting that 1930 (7:30 p.m.) precedes 2000 (8:00 p.m.).

Final Answer:
a, c, b, d