Educate Kids - What is the best way to get them obey?

I used to hate being around with kids and never think that I can get on well with them who tend to whine all day in and day out. Sometimes adults get tired and stressed out because their children continuously make noise and don't let you alone any seconds. As a result, you easily get angry. You can't stop your boiling annoyance. Sometimes you expect them to be silent or sleep for hours, which enables to have quiet time to take a break after hard time at work.

I am living with two kids. One is 13 years old and the other is 7 years old. The 7 year old kid is boy and he is a kind of rebellious child. He behaves badly in meals and never take a bath on his own. His parents pamper him so much that he should learn how to be independent instead of asking the old for help in every situation.