Schools 1)
A and B are digits in the number 30ABS. If this number is divisible by 225, find the sum of all
possible values of A.
A) 7
B) 11
C) 9
D) 10
E) 15

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?