Plan from the supplied facts
Fictional components A and B require 2–4 and 3–7 hours. Every combination inside these stated bounds is permitted, and no probability is supplied. Summing endpoints gives total 5–11 hours. The range does not state an 80% or 95% chance.
| Component | Minimum h | Maximum h | Probability supplied |
|---|---|---|---|
| A | 2 | 4 | No |
| B | 3 | 7 | No |
| Total | 5 | 11 | No |
Work through the choice
Endpoint addition uses the allowed joint combinations. If A’s maximum and B’s maximum cannot coexist, the upper bound needs that joint rule rather than a silent assumption.
Add C at 1–2 hours, still allowing all combinations. What range follows?
Show the worked answer
6–13 hours: 2+3+1=6 and 4+7+2=13. No likelihood for a point inside that range follows from the bounds alone.
Material to use in your plan
Use minimum, maximum and co-occurrence assumptions per component. Label the result a permitted envelope and leave confidence percentages blank unless a probability model is separately supplied.