In the sequence (4,12,36,x,324), what is the most likely value of x?

If increasing 20 by P percent gives the same result as decreasing 60 by P percent, what is P percent of 70?

A team won 45% of the first 80 games played. How many of the remaining 82 games will the team have to win in order to win 50% of all games it played?

An oculist charges $30 for an eye exam, frames, and glass lenses, but $42 for an eye exam, frames, and plastic lenses. If plastic lenses cost four times as much as glass lenses, how much do glass lenses cost?

4/7 of professors are male. The ratio of tenured: untenured is 2:5. If 1/5 of male professors are tenured, what fraction of female professors are untenured?