Been working on this problem for 2 days explain and show me how to do the work

Shane can shovel the driveway in 4 hours, but if his sister it would take 2 hours. how long would it take taylor to shovel the driveway alone

Which function has the domain x> -11?

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?