Thursday, March 18, 2010

Problem solving

Just finished watching "Die Hard With a Vengeance" (the one with Bruce Willis and Samuel L. Jackson), and noticed that the director did a piss-poor job of showing how McCain and Zeus got the 4 gallons of water into a 5 gallon jug when the only other container was a 3 gallon jug. So for the benefit of any math- or logic-impaired out there, here's how it works:
  1. Fill 3-gallon container.
  2. Empty 3-gallon into 5-gallon
  3. Refill 3-gallon
  4. Pour into 5-gallon until it's full.
  5. [3-g now contains 1 gallon: filled twice with 3 gallons (steps 1 and 3), emptied of 3 gallons once (step 2), then emptied of 2 gallons (step 4)]
  6. Empty 5-gallon.
  7. Pour rest of 3-gallon into 5-gallon.
  8. Fill 3-gallon, empty into 5-gallon
  9. [5-g now contains 4 gallons: 1 gallon (step 7) + 3 gallons (step 8)]
Simple, no?

4 comments:

leeann said...

Is this going to be on the final exam?

Dave said...

Yes, but possibly in the form of a word problem

leeann said...

I have an excuse note already prepared.

Teresa said...

I remember the first time I saw that movie and thinking... I'm too tired right now so I'm not gonna think about this. Heh. But I did wonder how much "leeway" there was on the exactness. Ain't no way they'd be able to be truly exact while pouring water between jugs in the park. Then I smacked myself in the head and told myself to "Stop it! It's a movie!" LOL.