A bouncy ball is dropped such that the height of its first bounce is 3 feet and each successive bounce is 77% of the previous bounce's height. What would be the height of the 5th bounce of the ball? Round to the nearest tenth (if necessary).

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?