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bonanova

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Offline Last Active Yesterday, 10:11 AM
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Topics I've Started

Driving man's delight - 2 a harder puzzle

15 May 2013 - 08:16 PM

I owe it to the Den to post at least one of these without error.
Possibly this one does that.

Give the longest route (sequence of city numbers) that visits all the cities
(a) not returning to starting city (sum of 7 distances - starting point matters)
(b) returning to starting city (sum of 8 distances - starting point does not matter)

This puzzle has more choices than the first one.

Cities lie clockwise on the perimeter of a 6x6 square:


6--O------O-------+--------O
   |3     4               5|
   |                       |
   |                       |
4--+                       +
   |                       |
   |                       |
   |                       |
2--O2                     6O
   |                       |
   |                       |
   |1              8      7|
0--O-------+-------O-------O
   |       |       |       |
   0       2       4       6



+----+---+---+
|City| x | y |   Distances:
+----+---+---+   8.485  1-5 3-7
| 1  | 0 | 0 |   7.211  2-5 3-6 3-8 4-7
| 2  | 0 | 2 |   6.325  1-4 1-6 2-7 4-8 5-8
| 3  | 0 | 6 |   6.000  1-3 1-7 2-6 3-5 5-7
| 4  | 2 | 6 |   5.656  4-6
| 5  | 6 | 6 |   4.472  2-4 2-8
| 6  | 6 | 2 |   4.000  1-8 2-3 4-5 5-6
| 7  | 6 | 0 |   2.828  6-8
| 8  | 4 | 0 |   2.000  1-2 3-4 6-7 7-8
+----+---+---+


Walking man's delight

15 May 2013 - 01:26 AM

Enough with traveling salesman who hate long road trips.

Mario Andretti has joined the team, and he loves to drive!

 

His route today comprises eight towns, placed at the corners of an octagon.

Here are their coordinates:

Attached File  salesman.gif   5.9K   27 downloads

Edit: 7 and 8 are labeled incorrectly. They should be switched.

 

+---+-+-+

City x y

+---+-+-+

 1   0 2

 2   0 4

 3   2 6

 4   4 6

 5   6 4

 6   6 2

 7   4 0

 8   2 0

+---+-+-+

The inter-city distances, to save some calculations, are N-S and E-W distances of 6, along with four different diagonal distances of 2.828, 4.472, 5.657 and 6.083 6.325

 

If Mario begins driving at city 1 (coordinates 0 2) and drives until he has visited them all, how far will he be able to drive, and what city will he visit last?

 

If his objective is to return to his hotel in City 1 after visiting the other cities, how long of a trip could he accomplish?


Slicing a pizza a whole different way

12 May 2013 - 09:35 AM

You want to divide a pizza into a number of slices, but you're tired of going through the center all the time. So you adopt the strategy of marking points on the circumference of the pie and making slices along all the chords that they pairwise create. At last week's pizza party you attempted to make 32 pizza chunks, from a very large pie, by this method. How many points did you have to mark off on the pizza's circumference to give you and your 15 guests at least 2 chunks each?

 

Bonus: The coveted bonanova gold star will be awarded if you give the formula for calculating pieces from points.

 

This gives you an idea:

Attached File  pizza.gif   6.64K   21 downloads


Sunny skies over Titan?

12 May 2013 - 09:06 AM

The findings of the Huygens probe indicate that Titan (Saturn's largest moon) has a nitrogenous atmosphere that periodically produces rain onto that moon's surface. Titan and Earth are the only known heavenly bodies with liquid rain. But given its hostile temperature of -180oC Titan's rain is not water, it's liquid methane. But enough of the cold facts.
 
The exciting part of this puzzle is that in 2004 you were given a large supply of beef jerky, a warm parka, and the job of being Titan's chief in-person, feet on the ground, up close and personal, weather observer. Upon your recent return, you reported your findings on Titan's rain activity. Let's call the days on Titan that it did not rain "sunny" days, even with the constant nitrogenous smog. (You grew up in Los Angeles.) You found that sunny days on Titan were followed by another sunny Titan day 29 days out of 30, (pss = 29/30), while rainy days were followed by another rainy day with probability prr = 0.7.
 
Like many heavenly satellites, Titan's rotation is tidally locked to its orbital period (16 Earth days.) If you were on Titan for say 9 Earth years, on about how many Titan days did you observe rain?

Cornering a ladder

09 May 2013 - 09:40 AM

Two hallways, of widths 4 and 6 feet, meet at a corner. You and a friend are borrowing a 14-foot ladder and need to get it past the corner. If the ends of the ladder are kept at the same height, is it possible to carry the ladder from one hallway to the next? What is the longest ladder that can pass?