Ways to tile a floor of area 9*3 with similar tiles of area 3*1?

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Discussion Overview

The discussion revolves around the problem of determining the total number of ways to tile a floor of area 9 by 3 using tiles of area 3 by 1. The focus includes mathematical reasoning and the exploration of recursive relationships in combinatorial tiling.

Discussion Character

  • Mathematical reasoning
  • Exploratory

Main Points Raised

  • Some participants express uncertainty about their solutions and seek clarification on the total number of ways to tile the specified area.
  • One participant proposes defining T(n) as the number of ways to tile an n by 3 rectangle with 3 by 1 tiles, providing initial values for T(1), T(2), and T(3).
  • A participant outlines a recursive approach to compute T(n) based on the placement of tiles, leading to the relation T(n) = T(n-1) + T(n-3).
  • From the recursive relation, the participant computes values for T(4), T(5), and concludes with T(9) = 19.
  • Another participant agrees with the recursive approach and suggests that it can be implemented using recursion.

Areas of Agreement / Disagreement

While there is some agreement on the recursive relationship and initial values, the overall question of the total number of ways to tile the area remains open to further exploration and verification, with no consensus on the final answer.

Contextual Notes

Participants have not fully defined the conditions of the tiles, such as whether they are all identical or if orientation matters, which may affect the interpretation of the problem.

injun_joe
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I've been wondering a lot, but I'm not satisfied with my solution.
Can anyone tell me the TOTAL number of ways to tile a floor of area 9*3 with similar tiles of area 3*1??
 
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Any1??
 
injun_joe said:
I've been wondering a lot, but I'm not satisfied with my solution.
Can anyone tell me the TOTAL number of ways to tile a floor of area 9*3 with similar tiles of area 3*1??

It would help if you could give a little more detail about the question. Are the tiles all different? Are you primarily concerned about tile orientation?
 
injun_joe said:
I've been wondering a lot, but I'm not satisfied with my solution.
Can anyone tell me the TOTAL number of ways to tile a floor of area 9*3 with similar tiles of area 3*1??
Let's define T(n) = the number of ways to tile an n by 3 rectangle with tiles of size 3 by 1.

By inspection, T(1) = T(2) = 1, and T(3) = 2.

Suppose n > 3. Let's say the rectangle is n units long in the X direction and 3 units high in the Y direction. Consider the tile placed at the lower left hand corner of the rectangle. The tile must be either placed vertically or horizontally. If it's placed vertically, with its long axis running parallel to the Y axis, then there are T(n-1) ways to tile the remaining (n-1) by 3 rectangle. If it's placed horizontally, with its long axis running parallel to the X axis, then there must be two more horizontal tiles stacked directly on top of it, and there are then T(n-3) ways to tile the remaining (n-3) by 3 rectangle. So T(n) = T(n-1) + T(n-3).

From these relations, we can compute T(4) = 3, T(5) = 4, ..., with the result T(9) = 19.
 
awkward said:
Let's define T(n) = the number of ways to tile an n by 3 rectangle with tiles of size 3 by 1.

By inspection, T(1) = T(2) = 1, and T(3) = 2.

Suppose n > 3. Let's say the rectangle is n units long in the X direction and 3 units high in the Y direction. Consider the tile placed at the lower left hand corner of the rectangle. The tile must be either placed vertically or horizontally. If it's placed vertically, with its long axis running parallel to the Y axis, then there are T(n-1) ways to tile the remaining (n-1) by 3 rectangle. If it's placed horizontally, with its long axis running parallel to the X axis, then there must be two more horizontal tiles stacked directly on top of it, and there are then T(n-3) ways to tile the remaining (n-3) by 3 rectangle. So T(n) = T(n-1) + T(n-3).

From these relations, we can compute T(4) = 3, T(5) = 4, ..., with the result T(9) = 19.


Thats correct! This can even be done with recursion.
 

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