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# A rectangular tiled floor consists of 70 square tiles. The

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Senior Manager
Joined: 02 Oct 2005
Posts: 290
A rectangular tiled floor consists of 70 square tiles. The  [#permalink]

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11 Nov 2005, 00:50
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Difficulty:

(N/A)

Question Stats:

60% (01:11) correct 40% (01:16) wrong based on 47 sessions

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A rectangular tiled floor consists of 70 square tiles. The rectangular floor is being rearranged so that 2 tiles will be removed from each row of tiles and 4 more rows of tiles will be added. After the change in layout, the floor will still have 70 tiles, and it will still be a rectangle. How many rows were in the tile floor before the change in layout?

A) 4

B) 7

C) 10

D) 14

E) 28
Intern
Joined: 20 Oct 2005
Posts: 10

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11 Nov 2005, 03:25
its D, rows should be 14, as then it would be 14 x 5[/quote]
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Joined: 30 Sep 2004
Posts: 1397
Location: Germany

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11 Nov 2005, 03:45
1
C)...tr=70...(t-2)(r+4)=70...solve for x=10...
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If your mind can conceive it and your heart can believe it, have faith that you can achieve it.
Senior Manager
Joined: 27 Jun 2005
Posts: 460
Location: MS

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11 Nov 2005, 16:18
1
C 10,

A) 4
before r = 4 then colum 70/4 = remainder ...no possible

B) 7
before r =7 then column 70/7 = 10

after the 4 rows are added and 2 columns are remved
(7+4)*(10-2) !=70 wrong

C) 10
before r =10 column = 70/10 = 7
after the 4 rows are added and 2 columns are remved
(10+4)*(7-2)= 14*5=70 Number of times remained same
D) 14

E) 28

hence C
Senior Manager
Joined: 02 Oct 2005
Posts: 290

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11 Nov 2005, 21:35
OA is C and cool_jonny009 has provided a good explanation.
Senior Manager
Joined: 07 Jul 2005
Posts: 376

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11 Nov 2005, 21:52
Use the following two equations

xy = 70 and (x+4)(y-2) = 70, where x is the number of rows and y is the number of columns.

Solving for x, I get x = 10

C!
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Joined: 20 Dec 2010
Posts: 1779
Re: PS: Rectangular floor + Tiles  [#permalink]

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23 Dec 2010, 10:34
c=10

x-> Number of rows
y-> Number of columns

xy=70

(x+4)(y-2)=70
xy+4y-2x-8=70
70+4y-2x-8=70
4y-2x-8=70-70
4y-2x-8=0 **** (i)
Multiply (i) by x
4xy-2x^2-8x=0
4*70-2x^2-8x=0
x^2+4x-140=0

We get x=10 and x=-14
x can't be negative.

x=10 Rows
y=7 Columns
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Re: A rectangular tiled floor consists of 70 square tiles. The  [#permalink]

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03 Aug 2017, 05:29
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Re: A rectangular tiled floor consists of 70 square tiles. The   [#permalink] 03 Aug 2017, 05:29
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