What is the median of this set of data one, two, five, six, nine

The cost c, in dollars, for bananas depends on the weight w,in pounds, of the bananas. this situation is represented by the function rule c=0.5w (graph each function rule.tell whether the graph is continuous or discrete)

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?

Can anyone explain to me how to do this? anything will .