Brain Teasers
Sir Mad and The Dragon
During the Medieval period of Madadian history the land was terrorised with strange creatures, like the legendary Georgian Dragon that roamed the hills of the lower Madadian Forest.
Young Sir Mad Ade, knight of the periodic table, was dispatched by the King to dispense with the infamous Dragon.
The task was not as straight forward as in may seem, as the Georgian Dragon had three heads and three tails. If this was not bad enough there was even more of a problem, the dragon had certain regenerative powers, so if one head is chopped off, a new head grows, also if Sir Mad Ade is to chop off one tail, two new tails grow.
If Sir Mad hacks off two tails, one new head grows. But if two heads are chopped off, nothing grows.
Young Sir Mad has with him a magical sword, blessed by the lady of the boating lake. The sword is capable of removing with a single blow either one head or two heads, or one tail or two tails, but never a combination of a head or a tail in one blow.
What is the smallest number of strokes required by Sir Mad Ade to chop off all heads and tails of the dragon, thus killing it?
Young Sir Mad Ade, knight of the periodic table, was dispatched by the King to dispense with the infamous Dragon.
The task was not as straight forward as in may seem, as the Georgian Dragon had three heads and three tails. If this was not bad enough there was even more of a problem, the dragon had certain regenerative powers, so if one head is chopped off, a new head grows, also if Sir Mad Ade is to chop off one tail, two new tails grow.
If Sir Mad hacks off two tails, one new head grows. But if two heads are chopped off, nothing grows.
Young Sir Mad has with him a magical sword, blessed by the lady of the boating lake. The sword is capable of removing with a single blow either one head or two heads, or one tail or two tails, but never a combination of a head or a tail in one blow.
What is the smallest number of strokes required by Sir Mad Ade to chop off all heads and tails of the dragon, thus killing it?
Answer
Sir Mad Ade managed it in nine strokes.The best way to achieve this is that all of the tails must be converted to heads in such a way that the dragon is left with an even number of heads.
The way Sir Mad did this in the smallest number of strokes was to first convert the three tails to six tails by using three one-tail strokes, then converting the six tails to three heads via three two-tail strokes. Finally, the now six-headed dragon can be killed with three two-head strokes.
Thus, total of nine strokes to chop off all heads and tails of the dragon.
Hide Answer Show Answer
What Next?
View a Similar Brain Teaser...
If you become a registered user you can vote on this brain teaser, keep track of which ones you have seen, and even make your own.
Solve a Puzzle
Comments
So, after nine strikes it's dragon kebab time?
Jan 24, 2004
Good thing some other knight, like say, "Sir Mathless", didn't get there first and give the dragon more heads by blundering a bit and then getting himself eaten. Fun teaser! I love a good story problem.
I don't get it? He chops off 2 heads, nothing grows. (HTTT). He then chops of 2 tails and 1 head grows (HHT). He now chops off 2 heads and nothing grows. (T) He now chops off the last tail. All heads and tails are removed so it is dead. Are you gonna say it grows another 2 tails after it is dead? This is kinda like the opposite problem of the frog vlimbing out of the well.
Feb 01, 2004
Well, Jimbo, there are certain advantages to being a mythological creature.
I think it can be solved in 7 actually (my mum suggested this so it must be right)
start by removing one tail to give HHHTTTT now 2 tails (HHHHTT) now 2 heads (HHTT) now 2 tails (HHH) now 2 heads (H) now the last head which gives (HH) which can be removed with the 7th blow.
Am I right?
(or rather my mum?)
start by removing one tail to give HHHTTTT now 2 tails (HHHHTT) now 2 heads (HHTT) now 2 tails (HHH) now 2 heads (H) now the last head which gives (HH) which can be removed with the 7th blow.
Am I right?
(or rather my mum?)
AAAAARRRRRRRRGGGHH!!!!
sorry thats wrong. I was thinking that if one head is removed it makes 2 heads grow not one.
sorry thats wrong. I was thinking that if one head is removed it makes 2 heads grow not one.
I think it can be done in 6 strokes.
Start: 3heads,3 tails
Step 1:Chop off 2 tails:Result:4Heads, 1tail
Step 2:Chop off remaining 1 tail: result: 4 Heads, 2 tails
Step 3:Chop off 2 tails,Result 6 heads
Step 4:Chop off 2heads,Result 4 heads
Step 5:Chop off 2Heads,Result 2 heads
Step 6:Chop off 2Heads,Result dead monster
Start: 3heads,3 tails
Step 1:Chop off 2 tails:Result:4Heads, 1tail
Step 2:Chop off remaining 1 tail: result: 4 Heads, 2 tails
Step 3:Chop off 2 tails,Result 6 heads
Step 4:Chop off 2heads,Result 4 heads
Step 5:Chop off 2Heads,Result 2 heads
Step 6:Chop off 2Heads,Result dead monster
Dishu, how do you go from four heads to six heads in step 3?
Cute teaser, but as others point out, how does the dragon grow new heads after it's dead? Anyway, I interpreted the problem as intended and got the intended answer.
Cute teaser, but as others point out, how does the dragon grow new heads after it's dead? Anyway, I interpreted the problem as intended and got the intended answer.
To post a comment, please create an account and sign in.
Follow Braingle!