Which of the following is a valid duration value?

• A. 30-45mins
• B. 30-60mins
• C. 60-120mins
• D. 15-30mins

Answer: (A)

Duration values show how long a task should take under normal conditions, and when there’s variability, they’re often given as a range in minutes. Expressing a time window with a lower and upper bound helps planners and crews estimate effort, allocate resources, and anticipate how long the job may actually take.

The choice 30-45mins is valid because it communicates a time window in minutes, giving both the minimum and maximum expected duration. This matches the common practice of allowing for slight variations in task completion time and keeps the unit clear.

Other ranges exist, but they either suggest time windows outside the typical scope for this task or don’t align with the standard formatting used for duration estimates in this context.