New PMP Question & Answers with explanation

There are 10 stakeholders within your project. As the project manager, you must therefore manage 45 communication channels. Two additional stakeholders have been added. How many more channels of communication must you manage?
Select one
Who developed the model that defines the stages of a team’s development?
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All of the following are true regarding project phases except for which one?
Select one
The project team recently participated in a working session to examine and document the effectiveness of risk responses in dealing with overall project risk. What is this working session, or meeting, called?
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A project manager meets with the project team to estimate the duration of activities identified to date. The project sponsor recently guided the project manager to present her with a duration estimate for the project that contains a high confidence level. What estimating technique is the project manager likely to use, assuming that the necessary information is available?
Select one