How do i simplify the ratio 10 : 20

On a piece of paper graph f(x)=5•(0.4)^x

What additional information could be used to prove abc =mqr using sas? check all that apply.

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?