Task1 start on Day1 and has a duration of 10 days, so the finish
date is Day10.
Task2, which is dependent on Task1, can start on Day11 . With a
duration of 30 days, Task2 will end on Day40.
Task3 and 4 are multiple successor tasks that can start after Task2
is done. Task2 end on Day40, so Task3 and 4 both can start on
Day41, Task3 has a duration of 5 days, and will end on Day45.
Task4 has a duration of 25 days and will not end until Day65.
Task5 depends on Task3 and 4, which are multiple predecessors.
Because Task5 depends on both tasks, it cannot start until the later
of the two tasks is complete. So Task5 cannot start until Day66.