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What is the area of square ABCD?

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What is the area of square ABCD? [#permalink]

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New post 17 Feb 2016, 03:35
1
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A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

93% (00:16) correct 7% (00:29) wrong based on 151 sessions

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Re: What is the area of square ABCD? [#permalink]

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New post 18 Feb 2016, 07:58
1
Bunuel wrote:
What is the area of square ABCD?

(1) The diagonal of square ABCD is \(5\sqrt{2}\)
(2) The perimeter of square ABCD is 20


Kudos for correct solution.



Let the length of square= L

(1) The diagonal of square ABCD is \(5\sqrt{2}\)

So L= 5........> Area =5*5=25

(2) The perimeter of square ABCD is 20..............> 4L=20...? L=5
Area= 25

Answer: D
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Re: What is the area of square ABCD? [#permalink]

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New post 18 Feb 2016, 16:45
1
Let the length of square= L

(1) The diagonal of square ABCD is 52√52

So L= 5........> Area =5*5=25

(2) The perimeter of square ABCD is 20..............> 4L=20...? L=5
Area= 25
WE KNOW THAT SQUARE FORMS 45, 45, 90 TRIANGLE , SO BASIC CONCEPT IS KNOWING ANY SINGLE SIDE WE CAN CALCULATE ALL OTHER SIDES..
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Re: What is the area of square ABCD? [#permalink]

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New post 18 Feb 2016, 19:32
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

What is the area of square ABCD?

(1) The diagonal of square ABCD is 5 √2
(2) The perimeter of square ABCD is 20


In the original condition, there is 1 variable(one side of square: x) for square, which should match with the number of equations. So you need 1 equation. For 1) 1 equation, for 2) 1 equation, which is likely to make D the answer. In fact, it is 99% that D is the answer.
For 1), from √2(x)=5√2, x=5, which is unique and sufficient.
For 2), from 4x=20, x=5, which is unique and sufficient.
Therefore, the answer is D.


 For cases where we need 1 more equation, such as original conditions with “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 59 % chance that D is the answer, while A or B has 38% chance and C or E has 3% chance. Since D is most likely to be the answer using 1) and 2) separately according to DS definition. Obviously there may be cases where the answer is A, B, C or E.
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Re: What is the area of square ABCD? [#permalink]

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New post 04 Aug 2016, 15:26
Statement 1 gives the length of diagonal of square as 5 \(\sqrt{2}\)
so side is 5 and area =\(side^2\) = 25
So sufficient
Statement 2 gives the perimeter as 20
perimeter = 4 * side = 20 so side is 5 and area = \(side^2\) = 25
So sufficient
Correct Answer - D
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What is the area of square ABCD? [#permalink]

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New post 04 Aug 2016, 17:56
Bunuel wrote:
What is the area of square ABCD?

(1) The diagonal of square ABCD is \(5\sqrt{2}\)
(2) The perimeter of square ABCD is 20


Kudos for correct solution.


Took 16 secs to solve..I think it's still more..

Stat 1: \(a\sqrt{2}\)(Diagonal of a sqaure) = \(5\sqrt{2}\).
a = 5.. Sufficient..

Stat 2: 4a = 20 , a = 5..Sufficient..

Option D is correct answer..
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Re: What is the area of square ABCD? [#permalink]

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New post 21 Feb 2017, 23:07
D
Statement 1 is sufficient
Side is 7
So area would be 49
Statement 2 is sufficient as well
Side is 7 as diagonal is sideroot2
So area 49

Sent from my SM-G600FY using GMAT Club Forum mobile app
Re: What is the area of square ABCD?   [#permalink] 21 Feb 2017, 23:07
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