Yippee ki-yay, Die Hard With a Vengeance was released 20 years ago, on May 19, 1995. The best Die Hard sequel—and maybe the best Die Hard?—brought Detective John McClane to New York for the first time, added a sidekick in the form of Samuel L. Jackson's Zeus and made audiences really think about math.

Credit: Everett Collection

At a key point in the film, McClane and Zeus are given a five-gallon jug and a three-gallon jug and asked to fill one with exactly four gallons of water to prevent a bomb from going off. So how do they solve the problem? Simple:

  1. Fill the five-gallon jug with water.
  2. Empty three gallons into the three-gallon jug, leaving two gallons in the five-gallon jug.
  3. Empty the three-gallon jug completely, and then refill it with the remaining two gallons from the five-gallon jug.
  4. Fill the five-gallon jug again.
  5. Empty one gallon from the five-gallon jug into the three-gallon jug.
  6. The five-gallon jug is left with exactly four gallons of water.

Happy anniversary, Die Hard!

Die Hard With a Vengeance
  • Movie
  • 131 minutes