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Updated on: 13 Sep 2022, 02:21
Originally posted by Raghavender on 03 Oct 2006, 05:34.
Last edited by Bunuel on 13 Sep 2022, 02:21, edited 2 times in total.
Last edited by Bunuel on 13 Sep 2022, 02:21, edited 2 times in total.
Edited the question and added the OA.
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B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
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Question Stats:
51% (01:32) correct
49%
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wrong
based on 2010
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In the figure above, line AC represents a seesaw that is touching level ground at point A. If B is the midpoint of AC, how far above the ground is point C?
(1) x = 30
(2) Point B is 5 feet above the ground.
Attachment:
Untitled.png [ 1.22 KiB | Viewed 26341 times ]
04 Oct 2006, 15:59
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Answer is B.
Statement 2 alone is suff.
lets say: BA= x
then CA = 2x (since B is the mid point of CA)
Triangle ACD(D is the point where the perpendicular dropped from C touches the ground) is similar to triangle ABE(E is the point where the perpendicular dropped from C touches the ground).
Therefore x/5=2x/z
or z=10
Statement 2 alone is suff.
lets say: BA= x
then CA = 2x (since B is the mid point of CA)
Triangle ACD(D is the point where the perpendicular dropped from C touches the ground) is similar to triangle ABE(E is the point where the perpendicular dropped from C touches the ground).
Therefore x/5=2x/z
or z=10
06 May 2015, 03:02
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Hi All,
For those of you who are not comfortable with the concept of similar triangles and its application, this question can be solved using application of simple trigonometric ratios.
In triangle ABD which is right angled at D, we can use \(Sin x = \frac{BD}{AB.}\)
Similarly, in triangle ACE which is right angled at E, we can use \(Sin x = \frac{CE}{AC}\)
From the above two equations, we can write \(\frac{BD}{AB} = \frac{CE}{AC}\) i.e. \(CE = \frac{(BD * AC)}{AB.}\)
Since \(AC = 2AB\), we can write \(CE = 2BD\).
So, for finding the height of point C from the ground we just need to know the height of point B from the ground.
We see that st-II provides us the height of B. Thus statement-II alone is sufficient to answer the question.
You can try out a similar question at a-squirrel-climbs-a-straight-wire-from-point-a-to-point-c-if-b-is-the-195315.html#p1517662
Hope its clear!
Regards
Harsh
For those of you who are not comfortable with the concept of similar triangles and its application, this question can be solved using application of simple trigonometric ratios.
In triangle ABD which is right angled at D, we can use \(Sin x = \frac{BD}{AB.}\)
Similarly, in triangle ACE which is right angled at E, we can use \(Sin x = \frac{CE}{AC}\)
From the above two equations, we can write \(\frac{BD}{AB} = \frac{CE}{AC}\) i.e. \(CE = \frac{(BD * AC)}{AB.}\)
Since \(AC = 2AB\), we can write \(CE = 2BD\).
So, for finding the height of point C from the ground we just need to know the height of point B from the ground.
We see that st-II provides us the height of B. Thus statement-II alone is sufficient to answer the question.
You can try out a similar question at a-squirrel-climbs-a-straight-wire-from-point-a-to-point-c-if-b-is-the-195315.html#p1517662
Hope its clear!
Regards
Harsh
the line AC as it goes up the angle degree is changing so logically angle ABD should be smaller than that of ACE .... is my reasoning incorrect ? 
if yes how can these angles be equal 
