emir is standing in a treehouse in looking down at a swing set in the yard next-door. The angle of depression from emir’s Highline to the swingset is 31.43°, and emir is 11 feet from the ground. How many feet is the base of the tree from the swing set

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?