Indicate a general rule for the nth term of the sequence when a1 = √3 and r = 2. 1. an = (√3)(2)n+1 2. an = (√3)(2)n-1 3. an = (2)(√3)n-1 4. an = (2)(√3)n+1

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?