$($a$)$ Following network shows a project having various activities in AOA format. Above

$15$

the arrow the alphabet denotes the activity name and the number in parentheses denotes the number of crew members required for carrying out the activity. The number below the arrow indicates time duration.

Draw a Gantt AOA chart from the above and construct a resource loading diagram. If the time duration of the project cannot be increased above $16$ days how many minium crew members are required in the team. If available crew members are only $7,$ how many days will be required to finish the project $?$