Suppose you plan to build a raised flower bed using landscape timbers, which come in 8-ft lengths. You want the bed’s outer dimensions to be 6 ft by 4 ft. and you will use three layers of timbers. The timbers are 6 in, by 6 in. in cross section, so if you make the bottom and top layers with 6-tt lengths on the sides and lengths on the ends, and the middle layer with 5-ft lengths on the sides and 4-ft lengths on the ends, you could build the bed out of the following lengths.
Plan A | |
Length | Number Needed |
3 ft | 4 |
4 ft | 2 |
5 ft | 2 |
6 ft | 4 |
(a) What is the smallest number of timbers you can buy to build your bed? How will you lay out the cuts? How much wood will you waste?
(b) If you overlap the corners in a different way, you can build the bed with this plan:
Plan B | |
Length | Needed |
3 ft | 2 |
4 ft | 4 |
5 ft | 4 |
6 ft | 2 |
Does plan B allow you to build the bed with fewer 8-ft timbers?
(c) What is the smallest length for the uncut timbers that would allow you to build the bed with no waste?
(a)
Answer to Problem 1EA
Solution: The minimum timber used is 8 timbers and the wastage of timber is 10 ft.
Explanation of Solution
Given: The provided data:
Explanation:
The length of the timber is 8 ft.
In the provided plan A:
4 blocks of length 3 ft, 2 blocks of length 4 ft, 2 blocks of length 5 ft, and 4 blocks of length 6 ft are needed.
Now, if a timber of length 8 ft is cut in two pieces of length 5 and 3 ft, then there is a requirement of 2 blocks of length 5 ft, so 2 timbers are required and cut into length of 5 and 3 ft, which also fulfilled the requirement of 2 blocks of length 3 ft.
As 4 blocks are required of length 3 ft but 2 blocks are provided from the above cutting, 1 timber is cut to get 2 more blocks to length 3 ft, and there will be a wastage of 2 ft timber.
As 2 blocks are required of length 4 ft, 1 timber is cut into two pieces of length 4 ft each.
Now, 4 blocks are required of length 6 ft each; therefore, 4 timbers are required to get 4 blocks of 6 ft each, and there is a wastage of 2 ft block from each timber.
Thus, the total number of timber used is equal to
Conclusion: The total timber used is 8 timbers, and the wastage of timber is 10 ft.
(b)
Answer to Problem 1EA
Solution: Still, the minimum timber used is 8 timbers and the wastage of timber is 10 ft.
Explanation of Solution
Given: The provided data:
Explanation:
The length of the timber is 8 ft.
In the provided plan A:
2 blocks of length 3 ft, 4 blocks of length 4 ft, 4 blocks of length 5 ft, and 2 blocks of length 6 ft are needed.
Now, if a timber of length 8 ft is cut in two pieces of length 5 and 3 ft, there is a requirement of 4 blocks of length 5 ft, so 4 timbers are required and cut into length of 5 and 3 ft, which also fulfilled the requirement of 2 blocks of length 3 ft, and there is a wastage of 6 ft timber.
As 4 blocks are required of length 4 ft. a timber is to be cut into two pieces of length 4 ft each; thus, 2 timbers are required to get 4 blocks of length 4 ft each.
As 2 blocks are required of length 6 ft, 2 timbersare cut into length of 6 and 2ft, and there is a wastage of 2 blocks of length of 2 ft each.
Thus, the total number of timber used is equal to
Conclusion: Still, the total timber used is 8 timbers, and the wastage of timber is 10 ft.
(c)
Answer to Problem 1EA
Solution: If the uncut timber is of 9 ft, there will be no wastage of timber.
Explanation of Solution
Given: Information provided in part (a) and part (b)
Explanation:
The required lengths of the timber blocks are 3, 4, 5, and 6ft.
So, when the length of the uncut timber is 8 ft, there is wastage in cutting a block of the required length; then, to minimize the waste, the smallest length of timber that is required is 9 ft because when the timber is of 9 ft, then if it is cut into two pieces of length 5 and 4ft, and timber can be cut into two pieces of length 3 and 6ft, which implies that there is no wastage of timber.
Conclusion: The smallest length of uncut timber that minimizes the wastage is 9 ft.
Want to see more full solutions like this?
Chapter 4 Solutions
Finite Mathematics (11th Edition)
Additional Math Textbook Solutions
Differential Equations: An Introduction to Modern Methods and Applications
Mathematics for the Trades: A Guided Approach (11th Edition) (What's New in Trade Math)
Discrete Mathematics and Its Applications ( 8th International Edition ) ISBN:9781260091991
Introductory Mathematics for Engineering Applications
Basic College Mathematics (12th Edition)
Finite Mathematics for Business, Economics, Life Sciences and Social Sciences Plus NEW MyLab Math with Pearson eText -- Access Card Package (13th Edition)
- When the length of each edge of a cube is increased by 1 cm, the volume is increase by 61 cm3. What is the length of each edge of the original cube?arrow_forwardMary Frances has a rectangular garden plot that encloses an area of 48 yd2. If 28 yd of fencing are purchased to enclose the garden, what are the dimensions of the rectangular plot?arrow_forwardA baseball diamond is really a square with sides of 90 feet. How far is it from home plate to second base, as shown?arrow_forward
- Elementary Geometry For College Students, 7eGeometryISBN:9781337614085Author:Alexander, Daniel C.; Koeberlein, Geralyn M.Publisher:Cengage,Algebra: Structure And Method, Book 1AlgebraISBN:9780395977224Author:Richard G. Brown, Mary P. Dolciani, Robert H. Sorgenfrey, William L. ColePublisher:McDougal LittellElementary AlgebraAlgebraISBN:9780998625713Author:Lynn Marecek, MaryAnne Anthony-SmithPublisher:OpenStax - Rice University
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALMathematics For Machine TechnologyAdvanced MathISBN:9781337798310Author:Peterson, John.Publisher:Cengage Learning,