To crash the project by a forth day we choose at an additional cost of * O D, $50 C, $115 E, $125 O A, $75 Crashing the project by 4 days results in one critical path "A-B-C-D-F" two alternative critical paths which are "A - B - E - F" & "A - C - D - F" one critical path "A-C-D-F" two alternative critical paths which are "A - D - F" & "A-C - E