Workspace System Design
Learning pathsA
COURSE CHECKPOINT · 5 QUESTIONS

Quiz: Numbers to Know

Apply Numbers to Know to concrete decisions. Choose an answer for every question, then review the explanations.

Visual checkpoint

Use this diagram to locate the state and failure boundaries tested by the questions. Answer all five questions before revealing feedback; the result is a study checkpoint rather than a certification.

Arrival rate → Queue backlog (adds work); Queue backlog → Service budget (bounded dispatch); Service budget → Completed work (removes work); Completed work → Retention bytes (stored results); Queue backlog → Deadline check (age vs promise)
Scroll to inspect the diagram, or open it at full size.

Figure — Arrival rate → Queue backlog (adds work); Queue backlog → Service budget (bounded dispatch); Service budget → Completed work (removes work); Completed work → Retention bytes (stored results); Queue backlog → Deadline check (age vs promise)

Review your reasoning

After checking answers, identify the incorrect assumption behind each missed question. Rewrite it as a rule with a concrete exception or failure case, then return to the lesson.

A queue contains 60,000 jobs, workers finish 500/s, and new work arrives at 300/s. How long to drain?

1. 86.4 million requests/day implies what average rate?
2. At 500 requests/s and average 0.2 s in system, what average concurrency is implied?
3. One million messages at 500/s need at least how long?
4. A 60,000-job backlog drains at 500/s while 300/s arrive. How long to clear?
5. At 12,000 arrivals/s and 8,000 completions/s, what happens over one hour?

Answers and your latest score are saved to your account when you check them. Completion records your attempt, not a passing certification.