I'm teaching D1 for the first time and had a query today that I could not answer... Page 253, Ex 8I, Question 3. After the first worker has finished activity C, why is activity F chosen over activity D, when D has the lowest late end time? This is skipped over in the worked solutions with no explanation. https://www.activeteachonline.com/default/player/splitzoom/id/750543/external/0 Thanks.