3) It's in the Hole! Cinderella Story! Gary Gopher wishes to find the quickest way to get to the compost bin from his home in his series of underground tunnels he has developed in a University professor's back yard. (Sometimes there are some very tasty morsels in the compost bin). Dogs and armadillo's prowl the area, so speed and staying underground is of the essence. Nodes in his tunnel network represent the pertinent features in the yard. The link/arc values represent 'effort' to move from node to node (say, measured in ergs?). Suggestion: GG may choose to move laterally in his tunnel network (e.g., between the holly and the redbud) but certainly wouldn't move backwards (e.g., sunburst locust to the small oak). You can model accordingly. The picture shows double arrows where appropriate. a) Create a LP model to find this least effort path from home to the compost bin for Gary G. b) Augment the model and force Gary G. to travel past two trees on his way to the compost bin. 10 Roses 16 Day Lillies 8 16 12 Big Oak Forsythias 9 Redbud 20 17 Hosts Home 15 12 10 Lilacs 11 18 Holly 18 18 7 Jasmine Compost Bin 16 Yews 18 Holstein Rock 22 22 25 12 8 Ferns Sunburst Locust Small Oak 15 20 Trees are 'ovals' in the picture.