题目
The network in Figure 3 shows the activities that need to be undertaken by a company to complete a project. Each activity is represented by an arc. The duration of the activity, in days, is shown in brackets. Each activity requires exactly one worker. The early event times and the late event times are shown at the vertices.
It is given that the total float on activity F is twice the total float on activity D.
It is also given that the total duration of the activities on the path BDFM is 10 days less than the duration of the critical path.
(a) Determine the value of and the value of . You must make your method and working clear.
(b) Draw a cascade chart for this project on Grid 1 in the answer book.
(c) Use your cascade chart to determine the minimum number of workers needed to complete the project in the shortest possible time. You must make specific reference to time and activities. (You do not need to provide a schedule of the activities.)
题目中文翻译
图 3 中的网络显示了公司完成项目需要进行的活动。每项活动由弧表示。活动的持续时间（单位：天）显示在括号中。每项活动恰好需要一名工人。最早事件时间和最迟事件时间显示在顶点处。
已知活动 F 的总时差是活动 D 总时差的两倍。
还已知路径 BDFM 上活动的总持续时间比关键路径的持续时间少 10 天。
(a) 确定 的值和 的值。必须清楚说明方法和计算过程。
(b) 在答案本的网格 1 上画出此项目的级联图。
(c) 使用级联图确定在最短时间内完成项目所需的最小工人数量。必须具体说明时间和活动。（不需要提供活动时间表。）