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geometry

by maria » Thu May 15, 2008 8:33 am
Eight square window panes of equal size are to be pieced together to form a rectangular French door. What is the perimeter of the door, excluding framing between and around the panes?
1. the area of each pane is 1 square foot.
2. the area of the door, excluding framing between and around the panes, is 8 square feet.

Pls help me.
Thanks so much.
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by aatech » Thu May 15, 2008 9:45 am
Should be E..

Lets consider Sq tiles being placed in following 2 ways...

1) 1 row of 8 tiles
2) 2 rows of 4 tiles each

Stmt 1 - Area of SQ tile is 1 => side = 1

For the first type of placement perimeter = 2(1+8) = 18
For the second type of pleacement perimiter = 2(2+4) = 12

SO INSUFF

Stmt 2 - For both type of placements area of door = 8 so same logic as STMT 1.. INSUFF

Together, does not help - INSUFF
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by codesnooker » Thu May 15, 2008 9:48 am
Ans is (D).

Both statements are alone sufficient.

The first statement provided you the area of each pane. So you can determine the length of the side of the pane. Once you know the length of side of the pane, then no matter how all the panes are arranged, you can determine the perimeter. SUFFICIENT.

Statement 2 gives the area of rectangular door = 8.

Again you have to concentrate to determine the length of the pane.

As it is rectangular door made by 8 panes so there is only way to make the door.

DD
DD
DD
DD

Area = Height X Breath = 2 X Breath X Breath = 8

Breath X Breath = 4
Breath = 2

So you know the length of the side of the pane. Hence, you can easily determine the perimeter of the door. SUFFICIENT.

Hence (D) is the answer.
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by aatech » Thu May 15, 2008 10:00 am
Door can be made in 2 ways

DDDDDDDD

or

DD
DD
DD
DD

Both are rectangular with different perimeter
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by maria » Thu May 15, 2008 10:01 am
@ codesnooker, do you think we will have different length of the French door if we piece eight panes in different ways? because we are asked to find the perimeter of the door not the pane itself. Do you think so? :?:
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by codesnooker » Thu May 15, 2008 10:04 am
Indeed you are correct. Only the area would remain same, no matter what is the shape of the door. Perimeter would change with the shape of the door.

Thanks for sharing the results.
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by codesnooker » Thu May 15, 2008 10:22 am
maria wrote:@ codesnooker, do you think we will have different length of the French door if we piece eight panes in different ways? because we are asked to find the perimeter of the door not the pane itself. Do you think so? :?:
Yes Maria, it could be of different length depend upon the arrangement of the block. Though I don't if FRENCH DOOR is of some specific arrangement or not. If it has some specific arrangement, then yes perimeter would be same, however if not then it would have different parameter according to the arrangement of the panes.

My apologizes for the wrong statement that we should just determine the length of side of the pane to get the perimeter. In reality, actually one should know the arrangement of the panes also.
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by arorag » Thu May 15, 2008 5:43 pm
ans should be C. If it's correct i can give explanation
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by codesnooker » Thu May 15, 2008 6:01 pm
Go ahead with your explaination
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by akshatsingh » Tue May 20, 2008 1:20 am
First glance..the answer is definitely not D.
either C or E.

the "framing between and around the panes" makes me chose E.

Whats the answer ?

A request...Please put the answer with the question as it helps to decide whether it needs another lookin as a viewer...Thanx :)
Aks
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by chidcguy » Wed May 21, 2008 11:02 am
It appears E to me.

1. the area of each pane is 1 square foot.

Different shapes like 8 D's in one row, in one column, 2X4 and 4X2 can be formed. Essentially perimeter keeps changing A & D are out

2. the area of the door, excluding framing between and around the panes, is 8 square feet.

The excluding framing between and around panes is just to add confusion and avoid Q's on that area from the test taker

Just saying that Length X breadth = 8. (2,4) (4,2) (1,8) (8,1) and even more as we dont know that he L & B are integers. Again B is out

Taking both together still does not rule either the 2 & 4 combo or 8 & 1 so we still have rectangles with two different L & B combined. That means 2 values for perimeter.
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