Your company is modifying its warehouse operations with the installation of an automated materials

handling system. Specific activities include selecting the vendor, redesigning the warehouse layout,

designing computer interface, installing the new equipment testing the new equipment, training

system operators, etc. The immediate predecessors and activity times in weeks are as follows

Activity A B C D E F G H I J K

Predecessors $--$ A$,$B C C E C D$,$F$,$G D$,$F H I

Activity time $6941210689744$

a$-$ Draw the project network $(10$ points$)$

b$-$ Find the critical path and the project completion time. $(15$ points$)$