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Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. If A is 25 kilometers east of N. which is 12 kilometers sout  Question banks Downloads My Bookmarks Reviews Important topics
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If A is 25 kilometers east of N. which is 12 kilometers sout [#permalink]
Expert's post 00:00

Question Stats: 76% (01:39) correct 23% (01:58) wrong based on 43 sessions

If A is 25 kilometers east of B, which is 12 kilometers south of C, which is 9 kilometers west of D, how far is it. in kilometers. from A to D?

A) $$20$$

B)$$5\sqrt{34}$$

C) $$5\sqrt{41}$$

D) $$10 \sqrt{13}$$

E) $$71$$
[Reveal] Spoiler: OA

_________________ Director Joined: 03 Sep 2017
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Re: If A is 25 kilometers east of N. which is 12 kilometers sout [#permalink]
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Given the instructions, the figure is a trapezoid with larger base 25km long, smaller base 17km long and height 12km long. We are asked to find the oblique side. In order to find it we can exploit the fact that drawing the height DH we get a triangle whose hypotenuse is AD. Thus, using Pitagora's theorem we get $$sqrt(12^2+18^2)$$ that is not equal to 20.
In order to be 20 the number under the square root should be 400. Thus, CD must be equal to 9 so that AH is equal to 16.
Is there a typo or am I wrong in my computations? Director Joined: 20 Apr 2016
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Re: If A is 25 kilometers east of N. which is 12 kilometers sout [#permalink]
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IlCreatore wrote:
Given the instructions, the figure is a trapezoid with larger base 25km long, smaller base 17km long and height 12km long. We are asked to find the oblique side. In order to find it we can exploit the fact that drawing the height DH we get a triangle whose hypotenuse is AD. Thus, using Pitagora's theorem we get $$sqrt(12^2+18^2)$$ that is not equal to 20.
In order to be 20 the number under the square root should be 400. Thus, CD must be equal to 9 so that AH is equal to 16.
Is there a typo or am I wrong in my computations?

Your reasoning is correct, even I landed up with the same solution.
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Rules for Posting https://greprepclub.com/forum/rules-for ... -1083.html Director Joined: 03 Sep 2017
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Re: If A is 25 kilometers east of N. which is 12 kilometers sout [#permalink]
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Just found the original source of the question there was a typo in the statement "which is 9 kilometers west of D".

Fixed
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Re: If A is 25 kilometers east of N. which is 12 kilometers sout [#permalink]
Founder  Joined: 18 Apr 2015
Posts: 6874
Followers: 114

Kudos [?]: 1332 , given: 6293

Re: If A is 25 kilometers east of N. which is 12 kilometers sout [#permalink]
Expert's post
IlCreatore wrote:
Just found the original source of the question there was a typo in the statement "which is 9 kilometers west of D".

Fixed

Thanks. Often these questions are difficult to figure out as they are written, they are not clear. Thank you so much for the fixing.

Back to the question

Attachment: direction.jpg [ 10.1 KiB | Viewed 3694 times ]

BE 9, AE= 16, and DE= 12. Finally, DA= 20, because right triangle AED is a 3-4-5 triangle in which each side is multiplied by 4. If you don't realize that, use the Pythagorean theorem to get DA $$(DA)^2 = (AE)^2 + (DE)^2 = 256 + 144 = 400$$

DA = 20.
_________________ Re: If A is 25 kilometers east of N. which is 12 kilometers sout   [#permalink] 29 Sep 2017, 06:58
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