Q$2.(6$ marks$)$: A construction company obtained a contract to build a small house. The activity sequence with their duration and related costs, which are given in the following table:

NOTE: Use your UOB ID number, the last two numbers for activity $O$ duration $($ZY$)$ below, for example if your ID of UOB is ${20170935}_{?}$ then the $ZY$ here equal ${35}_{?}$

$\backslash$table$[[$Activity$,$Precedence,Duration $($Weeks$)],[$ID$,(I,J)$