New PMP Question & Answers with explanation

Your project's primary constraint is quality. To make certain the project team members don't feel too pressed for time and to avoid schedule risk, you decide to use which of the following activity estimating tools?
Select one
You are the project manager for Changing Tides video games. Your project is a bit ambiguous at first. It's similar in complexity and magnitude to a project that the team members worked on last year. The key stakeholder wants to be actively involved and be able to modify the requirements as the project progresses. The team is ready to define and estimate activities. Which of the following statements are true?
Select three
You are the project manager for Changing Tides video games. You are in the process of breaking the work packages into activities. Which of the following options are true?
Select two
Which of the following is not a major step of decomposition?
Select one
Your company provides answering services for several major catalog retailers. The number of calls coming into the service center per month has continued to increase over the past 18 months. The phone system is approaching the maximum load limits and needs to be upgraded. You've been assigned to head up the upgrade project. Based on the company's experience with the vendor who worked on the last phone upgrade project, you're confident they'll be able to assist you with this project as well. Which of the following is true?
Select one