Your College's Math Club Consists of Four Voting Members: the President

Your college's Math Club consists of four voting members: the president, vice president, secretary, and treasurer. The president's vote counts four times as much as the secretary and treasurer's votes and two times as much as the vice-president's vote. If the secretary and treasurer each have the exactly one vote and any motion needs at least six favorable votes in order to be passed, then give the weighted voting system which models this scenario.