In which league did the player who weighs 40% less than the heaviest player and whose height is 80 inches play?
weigh 40% less than the heaviest player refers to weight = Multiply(Max (weight), 0.6); league refers to lgID
SELECT T2.lgID FROM players AS T1 INNER JOIN players_teams AS T2 ON T1.playerID = T2.playerID GROUP BY T2.lgID, T1.weight HAVING T1.weight = MAX(T1.weight) - MAX(T1.weight) * 0.4