A contractor must complete the excavation of a family dwelling within 6 weeks or the project will be delayed. The task will take 3 weeks to complete. The total length of the project is 8 months. What is the total float time of this task?

A contractor must complete the excavation of a family dwelling within 6 weeks or the project will be delayed. The task will take 3 weeks to complete. The total length of the project is 8 months. What is the total float time of this task?