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.
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
01 Sep 2017, 07:48
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
77% (02:12) correct
23%
(02:19)
wrong
based on 89
sessions
History
Date
Time
Result
Not Attempted Yet
A 25-foot ladder is placed against a vertical wall of a building, with the bottom of the ladder standing on concrete 7 feet from from the base of the building. If the top of the ladder slips down 4 feet, then the bottom of the ladder will slide out
(A) 4 ft
(B) 5 ft
(C) 6 ft
(D) 7 ft
(E) 8 ft
(A) 4 ft
(B) 5 ft
(C) 6 ft
(D) 7 ft
(E) 8 ft
01 Sep 2017, 08:25
Kudos
Bookmarks
The ladder when inclined against the wall forms a right triangle - the ladder being the hypotenuse, the vertical wall and ground being the other 2 sides of the right triangle.
the base is given as 7 feet. Using this info we can calculate the vertical height by applying Pythagoras theorem. Therefore height is 24 feet (easier to find this if we know the 25-24-7 right triangle). If the ladder slips by 4 feet the height is now 20 feet and the ladder length is the same (25 feet). the new base can again be calculated by Pythagoras theorem or by simply applying the 3-4-5 multiple concept of right triangle.
thus we can calculate the new base as 15 feet.
Therefore the ladder has slipped by 8 feet (15-7).
Ans is E
Please guide if there is a faster way to solve this.
the base is given as 7 feet. Using this info we can calculate the vertical height by applying Pythagoras theorem. Therefore height is 24 feet (easier to find this if we know the 25-24-7 right triangle). If the ladder slips by 4 feet the height is now 20 feet and the ladder length is the same (25 feet). the new base can again be calculated by Pythagoras theorem or by simply applying the 3-4-5 multiple concept of right triangle.
thus we can calculate the new base as 15 feet.
Therefore the ladder has slipped by 8 feet (15-7).
Ans is E
Please guide if there is a faster way to solve this.
01 Sep 2017, 08:30
Kudos
Bookmarks
Bunuel
From Pythagoras
\(AC^2=AB^2+BC^2\)
625-49=576
AB=24
From another triangle
\(25^2= 20^2+(7+x)^2\)
\(625=400 + (7+x)^2\)
\((7+x)^2= 225\)
x=8
Attachments
Solution.jpg [ 18.38 KiB | Viewed 18411 times ]
