5 A group of friends want to prepare a meal. They start preparing the meal at 6:30 pm Activities to prepare the meal are shown in Figure 1 below.
\begin{table}[h]
\captionsetup{labelformat=empty}
\caption{Figure 1}
| Label | Activity | Duration (mins) | Immediate predecessors |
| A | Weigh rice | 1 | - |
| \(B\) | Cook rice | 18 | \(A\) |
| C | Drain rice | 1 | B |
| D | Chop vegetables | 10 | - |
| \(E\) | Fry vegetables | 12 | |
| \(F\) | Combine fried vegetables and drained rice | 1 | |
| G | Prepare sauce ingredients | 4 | - |
| \(H\) | Boil sauce | 12 | |
| \(I\) | Serve meal on plates | 2 | |
\end{table}
5
- Use Figure 2 shown below to complete Figure 1 above.
5
- (ii) Complete Figure 2 showing the earliest start time and latest finishing time for each activity.
\begin{figure}[h]
\captionsetup{labelformat=empty}
\caption{Figure 2}
\includegraphics[alt={},max width=\textwidth]{5a826f8b-4751-4589-ad0a-109fc5c821f2-06_700_1650_1781_194}
\end{figure}
5 - State the activity which must be started first so that the meal is served in the shortest possible time.
Fully justify your answer.
5
- (ii) Determine the earliest possible time at which the preparation of the meal can be completed.
Question 5 continues on the next page
5 - The group of friends want to cook spring rolls so that they are served at the same time as the rest of the meal. This requires the additional activities shown in Figure 3.
\begin{table}[h]
\captionsetup{labelformat=empty}
\caption{Figure 3}
| Label | Activity | Duration | Immediate predecessors |
| J | Switch on and heat oven | | - |
| K | Put spring rolls in oven and cook | | |
| \(L\) | Transfer spring rolls to serving dish | | |
The spring rolls must cook in the hot oven for 8 minutes.
It takes 30 seconds to transfer the spring rolls to a serving dish.
5 - Complete Figure 3 above.
5
- (ii) Determine the latest time at which the oven can be switched on in order for the spring rolls to be served at the same time as the rest of the meal.
[0pt]
[2 marks]
\includegraphics[max width=\textwidth, alt={}, center]{5a826f8b-4751-4589-ad0a-109fc5c821f2-09_2488_1716_219_153}