Q.Construct the network for the projects consisting of various activities and their precedence relationships are as given below :
A, B, C can start simultaneously $A<F,E$ ; $B<D,C$ ; $E,D<G$

Draw start node 1; A: 1-2, B: 1-3; from 2 emerge E, F; from 3 emerge C, D; E and D merge at node 4, then G; C, F, G terminate at end node 5.

Given precedence relations: A, B, C may start together; $A<F,E$; $B<D,C$; $E,D<G$.

Step 1 — identify starting activities.

Activities with no predecessor start from the initial event. From the relations, A and B have no predecessor. (C is shown as a successor of B via $B<C$; this contradicts the words "C starts simultaneously," so we follow the precedence relations, which are the binding data — see the note below.)

Step 2 — lay out the events (nodes).

• Node 1 = start event. A and B start here.
• A: $1\to2$
• B: $1\to3$

Step 3 — place the successors.

• $A<E,F$: E and F begin after A (at node 2). E: $2\to4$, F: $2\to5$.
• $B<D,C$: D and C begin after B (at node 3). D: $3\to4$, C: $3\to5$.
• $E,D<G$: both E and D must finish before G, so E and D merge at node 4; G: $4\to5$.

Step 4 — network diagram (event–activity list).