Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Nov 2007:30 AM PST
-08:30 AM PST
Learn what truly sets the UC Riverside MBA apart and how it helps in your professional growth
Nov 2211:00 AM IST
-01:00 PM IST
Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies Tackle difficult RC & MSR with confidence Excel in timed test environment- Nov 23
11:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease. 
Nov 2510:00 AM EST
-11:00 AM EST
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors.
20 Oct 2021, 02:00
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
45%
(medium)
Question Stats:
66% (01:56) correct
34%
(01:59)
wrong
based on 157
sessions
History
Date
Time
Result
Not Attempted Yet
A hiker is trying to determine the height of a vertical cliff using similar triangles. If he holds his 2-meter high staff perpendicular to the ground so that the end of the cliff's shadow coincides with the end of the staff's shadow, what is the height of the cliff?
(1) The staff's shadow is 5 meters long.
(2) The cliff's shadow is 10 times as long as the staff's shadow.
Attachment:
1.jpg [ 4.99 KiB | Viewed 3514 times ]
03 Nov 2021, 06:41
Kudos
Bookmarks
This question is a part of Are You Up For the Challenge: 700 Level Questions collection.
15 Dec 2021, 02:38
Kudos
Bookmarks
Call the cliff's height = H
The staff's height = 2
the Shadow from the bottom far left of the figure up to the point of the staff's intersection ("cliff's shadow") = C
the shadow that the staff makes - from the point of the staff's intersection to the far bottom right-end of the figure = S
The smaller right triangle is Similar to the Entire Triangular Figure - All three Angles are Congruent (A-A-A Postulate)
accordingly, the corresponding lengths for each triangle that is across from the congruent angle will be proportional:
2 / S = H / (C + S)
what is H = ?
s1: gives us the staff's shadow as 5 meters long
S = 5
2/5 = H / (C + 5)
still not enough information to determine a unique value for H = height of cliff
NOT Sufficient
S2: the cliff's shadow is 10 times the length of the staff's shadow
C = 10(S) ---> plugging these values into the Given Proportion we set up:
2 / S = H / (C + S)
2 / S = H / (10S + S)
2 / S = H / 11S ---> the Variable S cancels in the DEN on both sides of the Proportion
2 / 1 = H / 11 --> H = 22 meters
-B- S2 Sufficient alone to get a unique value for the Height of the Cliff
The staff's height = 2
the Shadow from the bottom far left of the figure up to the point of the staff's intersection ("cliff's shadow") = C
the shadow that the staff makes - from the point of the staff's intersection to the far bottom right-end of the figure = S
The smaller right triangle is Similar to the Entire Triangular Figure - All three Angles are Congruent (A-A-A Postulate)
accordingly, the corresponding lengths for each triangle that is across from the congruent angle will be proportional:
2 / S = H / (C + S)
what is H = ?
s1: gives us the staff's shadow as 5 meters long
S = 5
2/5 = H / (C + 5)
still not enough information to determine a unique value for H = height of cliff
NOT Sufficient
S2: the cliff's shadow is 10 times the length of the staff's shadow
C = 10(S) ---> plugging these values into the Given Proportion we set up:
2 / S = H / (C + S)
2 / S = H / (10S + S)
2 / S = H / 11S ---> the Variable S cancels in the DEN on both sides of the Proportion
2 / 1 = H / 11 --> H = 22 meters
-B- S2 Sufficient alone to get a unique value for the Height of the Cliff
