Which term describes the failure by either the buyer or the seller to perform part or all of the duties of a contract?

Which is true about a work breakdown structure?

A given schedule activity is most likely to last four weeks. In a best-case scenario, the schedule activity is estimated to last two weeks. In a worst-case scenario, the schedule activity is estimated to last 12 weeks. Given these three estimates, what is the expected duration of the activity?

An organization initiates a large project in a developing country The project manager, who is also the local stakeholder is very supportive of this project During project execution the project manager is transferred to another country The new project manager is less supportive of the project because it uses many local resources who could be focusing on other daily responsibilities What document should the project manager review?

An experienced project manager is preparing a kick-off meeting for a new service assessment. A high-level description of the service has been provided.
What should the project manager do next?