There are three (and only three) paths through a network

1. There are three (and only three) paths through a network (project), each with a probability of completion in less than 24 months as indicated:
a. S-a-b-F P1(<24) = .95
b. S- d-e-F P2(<24) = .85
c. S- g-h-F P3(<24) = .90
If the tasks are independent, what is the probability of the network being completed within 24 months? Note: S is the start node, F is the finish node.
2. You have been assigned to estimate the cost of installing fiber optic cable in a country. Fortunately, you have done a number of similar projects in this area in the past and you have accumulated the following parametric cost estimates based on this experience:
Mobilization/demobilization Cost = $10,000
Buried cable construction:
Cost per kilometer = $10,000 Sand
Cost per kilometer = $17,500 Sand & Clay
Cost per 100 meters = $ 5,500 Rock
Overhead cable installation:
Cost per kilometer = $ 7,500 
Cost per Road Crossing = $12,500 
Cost per pipeline Crossing = $ 5,000
The scope of the new project is as follows:
Predominately sand 150 km
Predominately sand & clay 100 km
Rock 500 meters
overhead XXXXXcrossings 3
pipeline crossings 5
Estimate the cost of construction for this project. Assume the estimates are fully loaded, ie they include labor, materials, applicable indirect costs such as overhead, etc. Must show your work.