GeekDad Puzzle Of The Week Solution: 3 Miners and a Hovercraft

Welcome back puzzlers ! Lets cut right to the chase and announce the winner of this weeks $50.00 ThinkGeek gift certificate is Thomas Prebeck who correctly solved the puzzle in 13 steps. Lets look at the puzzle again ...

Three competing dilithium miners were returning to their transports when a group of claim jumpers tried to steal their daily take. The miners valiantly fought off the claim jumpers but in the battle their transports were rendered useless. The only vehicle that was not damaged was the claim jumpers’ hovercraft. The miners need to get across the chasm with their crystals. Problem in the hovercraft will only hold 2 miners or 1 miner and his crystals. The Andorian miner had 80 Kg of crystals, the Romulan had 50 Kg and the Human had 30 Kg. They do not trust each other enough to leave one miner alone with more than his share of the crystals it’s OK to leave two alone because they’ll keep each other honest. Can you figure out how to get them across the chasm in the fewest number of trips? Here are the rules again:

1. You can only use the hovercraft
2. The hovercraft can hold 2 miners or 1 miner and a load of crystals
3. Each load of crystals must remain the same. No splitting them
4. No 1 Miner can be left alone with more than his share of the crystals.
5. Use the fewest number of trips possible

A few points here. Number 4 means they can't be left alone, even in the hovercraft. The human cannot take the Romulan's crystals across. It also means the Andorian can't take his crystals then return for someone else's crystals. He would be left alone on the other side with both loads of crystals.

1. Romulan takes 50Kg Across and leaves it on the other side
2. Romulan returns
3. Andorian takes 30 Kg and leaves it on the otherside
4. The Andorian returns
5. The Human and The Romulan go across
6. The Human returns with his 30 Kg
7. The Andorian goes across with his 80 Kg
8. The Romulan returns with his 50 Kg
9. The Human and the Romulan go across
10. The Andorian returns
11. The Andorian goes across with the 30 Kg
12. The Romulan returns
13. The Romulan goes across with his 50 Kg

There are other variations that satisfy the requirements but they still take 13 steps. This one has the added benefit that no two miners are left with more than their combined share (i.e. The Romulan and the Human are never left with more than 80 Kg)

As always I want to thank all the puzzlers who participated and remind you to stay tuned because Dave Banks is gonna be back next week with a new conundrum to confound confuse and complicate things.