What is x=5/2 plz answer

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

What is the prime factorization of 230

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?