Ok, so I'm having a hard time solving a problem that came in the puzzlOr edition of April 2016 called "Cell Towers", it's an integer, binary and goal programming problem where you have to assign...

Ok, so I'm having a hard time solving a problem that came in the puzzlOr edition of April 2016 called "Cell Towers", it's an integer, binary and goal programming problem where you have to assign celltowers to a city and cover at least 70% of al neighborhoods. The problem needs of course to minimize the number of cell towers installed and fulfill the goal of covering 70% of all neighborhoods. I'm going to post the link of the problem, since it's easier to visualize the problem in the picture that it has. http://www.puzzlor.com/2016-04_CellTowers.html