how do we solve for part (iii) ?

3. Consider the following information for a development project: Activity Immediate Normal time Crash time Normal cost predecessor(s) (weeks) (weeks) ($) A 12 10 50 000 A 10 8 140 000 B 12 9 120 000 A 8 9 D 60 000 E D 12 10 70 000 F CE 5 5 80 000 G 6 6 60 000 Crash cost ($) 90 000 170 000 180 000 70 000 95 000 80 000 60 000 (1) Draw the network diagram. [4] () Find the critical path and determine the expected project completion time and corresponding 16) cost. (1) of the company wants to complete the project in 41 weeks, find the optimal crash time and (10) cost