Help with Probabilities of a Decision Tree - No Cost Between Links 3-14

[mk001]

Could someone please show me how they arrive at the probabilities attached to the branches of this nodes.
Why is there no cost between on link 3,4,5,10,11,12,13,14 --------is this correct ?

The link to this tree is below

http://www.me.utexas.edu/~jensen/ORMM/computation/unit/decision/example.html

ps iwas of the opinion that this was an lp problem

 

[EnumaElish]

Could someone please show me how they arrive at the probabilities attached to the branches of this nodes.

It looks like the prob's are inputs (data) and you are to take them as given, just like the fictional costs stated on the diagram.