Arrange the following times in ascending chronological order (24-hour format). (a) 0640 hrs (b) 1930 hrs (c) 1335 hrs (d) 2000 hrs

Introduction / Context:
Chronological ordering in 24-hour time requires comparing hours first and then minutes within equal hours. The goal is earliest to latest.

Given Data / Assumptions:

• Times: 0640, 1335, 1930, 2000.
• Format is HHMM in 24-hour time.

Concept / Approach:
Order by hour; within same hour, order by minutes. Morning hours (00–11) come before afternoon (12–17), which come before evening/night (18–23).

Step-by-Step Solution:
0640 is the smallest hour (06).Next is 1335 (13:35).Then 1930 (19:30).Finally 2000 (20:00).

Verification / Alternative check:
Convert to minutes since midnight: 400, 815, 1170, 1200. Sorted list matches a → c → b → d.

Why Other Options Are Wrong:
Any order placing 2000 before 1930 or 1335 before 0640 violates ascending order.

Common Pitfalls:
Confusing 24-hour with 12-hour format, or misreading 1930 as 7:30 AM.

Final Answer:
a, c, b, d