When Joe stands 12 meters away from a lamp post, his shadow is 3 meters long. If the lamp post is 9 meters high, what is Joe’s height in meters?
A) 13/8
B) 5/3
C) 9/5
D) 16/9
E) 9/4
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Joe and the lamp post
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Brent@GMATPrepNow
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vivek.kapoor83
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parallel_chase
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I totally agree with cramya's solution as posted above. Just want to elucidate the fact:
after drawing the figure, we get two similar triangles, with the same base and having 1 angle of 90 degrees each, one with base 12 and another with base 3.
The triangle with base 12 has a height 9.
Therefore,
12/9 = 3/x
x = 9/4.
Hence E.
after drawing the figure, we get two similar triangles, with the same base and having 1 angle of 90 degrees each, one with base 12 and another with base 3.
The triangle with base 12 has a height 9.
Therefore,
12/9 = 3/x
x = 9/4.
Hence E.
No rest for the Wicked....
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Brent@GMATPrepNow
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The answer isn't E, but you are correct about the similar triangles.
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parallel_chase
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vivek.kapoor83
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is the ans C...i solved it by trignometry.
after drawing fig and solving by Tangent x = p/b =9/15
and then using similar trinangle concept and using the vaule of tan x
i got it to C...is it the rite choice.9/5
after drawing fig and solving by Tangent x = p/b =9/15
and then using similar trinangle concept and using the vaule of tan x
i got it to C...is it the rite choice.9/5
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Brent@GMATPrepNow
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Nice work.
There are two similar triangles:
Triangle 1: Height = 9 (lamp post) and base = 15 (12 meters PLUS 3 meter shadow)
Triangle 2: Height = x (Joe) and base = 3 (shadow).
We get 9/15 = x/3 (or 9/x = 15/3 . . . etc)
Solve for x to get 9/5 (C)
There are two similar triangles:
Triangle 1: Height = 9 (lamp post) and base = 15 (12 meters PLUS 3 meter shadow)
Triangle 2: Height = x (Joe) and base = 3 (shadow).
We get 9/15 = x/3 (or 9/x = 15/3 . . . etc)
Solve for x to get 9/5 (C)
Brent Hanneson - Creator of GMATPrepNow.com
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vivek.kapoor83
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was trigonometry d rite approach here..coz we use to solve it in school classes..similar ques i rem..
