Please help on below question related to Software Project Management :

(b) A well-known software house is upgrading a software product that will update an existing system at a client's site. An outline plan for the upgrading of the existing system has been drawn up, with 10 main tasks, as follows: Task A Write the system spec for the upgraded part (6 weeks) Task B Implement the upgraded modules (10 weeks) Task C Develop system test data (6 weeks) Task D Prepare user manuals (4 weeks) Task E Design and develop a data migration program (8 weeks) Task F Carry out system testing (3 weeks) Task G Train all users (4 weeks) Task 1 Test the data migration program (4 weeks) Task I User acceptance testing (3 weeks) Task J Upgrade the system (1 week) Tasks B, C, D and E are all dependent on task A. Task F cannot start until tasks B and Care both completed. Task G cannot start until tasks B and D are both completed. Task H is dependent solely on task E. Task I cannot start until tasks F, G and H are all completed. Task J is dependent solely on task I. i) Draw an Activity on Node diagram for this project, showing all dependencies and the earliest start time, latest finish time, duration and float for each task. [5 marks] ii) Highlight the critical path and calculate its duration [2 marks]