Answer
300
Work Step by Step
Sequence matters, it is a permutation problem.
Case1: use 3 flags, $_5P_3$=60
Case2: use 4 flags, $_5P_4$=120
Case3: use 5 flags, $_5P_5$=120
The total is the sum of all cases: 300
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.