When choosing team members for a group task, how do you ensure fairness, and how does a constitution aim to ensure fair representation in government?

To ensure fairness when peaking group members, the best criteria to focus on are experience and how well they will work with others. Someone who doesn't do their work and takes advantage of the others' aptitudes to get a high score is not someone you should pick for a group. In government, we should also elect those who seem best fit for the job, and thus, best fit to represent the people. If the retirement age is 65, that is, if we think 65-year olds are incapable of being productive workers, then why do we have a president in his 80s? Why are the majority of our politicians old white people when the average age in the US is 38 years old?