4. You have been recently been assigned to provide an accurate project schedule for constructing a new 50-story casino, in Las Vegas, Nevada. You are evaluating the network diagram for the construction project, and are using the forward pass calculations to construct the schedule. You are trying to calculate the earliest start time for laying the foundation of the building. The expected duration for this task is 150 days. The task must be completed within 300 days, while the expected completion is within 220 days. The latest finish time is 200 days. Based on this information, what is the earliest start time of this task?