[问答题]
A package delivery company offers 2
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j 3j5 kmghf4*j0w.pgg9- 5 cowcci6avnumber of cities in close proximity. The directed graph below shows four cities served (A-D)
j94j.vi 6opc gj3h5gm* -0wak5wcgfc and the routes of delivery between them.
1. Find an adjacency matrix $\boldsymbol{A}$ for the shipping network.
2. Find the number of ways it is possible to ship a package from city $\mathrm{C}$ to city $\mathrm{A}$ using exactly three delivery routes.
3. (1) Find the matrix $\boldsymbol{S}_{3}$ , where $\boldsymbol{S}_{3}=\sum_{i=1}^{3} \boldsymbol{A}^{i}$ .
(2) Hence write down the number of ways it is possible to deliver a package from city A to city D using three or less delivery routes.
(3)State all possible ways to ship a package from city A to city D using three or less delivery routes.
