GRE Prep 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.
A ladder of a fire truck is elevated to an angle of 60° and
[#permalink]
10 Jun 2020, 10:10
10 Jun 2020, 10:10
Expert Reply
1
Bookmarks
00:00
Question Stats:
92% (01:34) correct
7% (01:09) wrong based on 27 sessions
Hide Show timer Statistics
A ladder of a fire truck is elevated to an angle of 60° and extended to a length of 70 feet. If the base of the ladder is 7 feet above the ground, how many feet above the ground does the ladder reach?
(A) 35
(B) 42
(C) \(35\sqrt{3}\)
(D) \(7 + 35\sqrt{3}\)
(E) \(7 + 42\sqrt{3}\)
(A) 35
(B) 42
(C) \(35\sqrt{3}\)
(D) \(7 + 35\sqrt{3}\)
(E) \(7 + 42\sqrt{3}\)
Re: A ladder of a fire truck is elevated to an angle of 60° and
[#permalink]
10 Jun 2020, 10:10
10 Jun 2020, 10:10
Expert Reply
Post A Detailed Correct Solution For The Above Questions And Get A Kudos.
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: A ladder of a fire truck is elevated to an angle of 60° and
[#permalink]
10 Jun 2020, 10:21
10 Jun 2020, 10:21
2
Carcass wrote:
A ladder of a fire truck is elevated to an angle of 60° and extended to a length of 70 feet. If the base of the ladder is 7 feet above the ground, how many feet above the ground does the ladder reach?
(A) 35
(B) 42
(C) \(35\sqrt{3}\)
(D) \(7 + 35\sqrt{3}\)
(E) \(7 + 42\sqrt{3}\)
(A) 35
(B) 42
(C) \(35\sqrt{3}\)
(D) \(7 + 35\sqrt{3}\)
(E) \(7 + 42\sqrt{3}\)
Here's an idea of what's going on....
When we compare the big triangle with the BASE 30-60-90 special triangle (which you must memorize for test day!), we can see that the hypotenuse of the big triangle is 35 times as long as the hypotenuse of the base triangle.
This means the big triangle is 35 times the size of the base triangle.
This means that, on the big triangle, the side opposite the 60 degree angle must be 35√3
Now before we (incorrectly) choose answer choice C, we must keep in mind that the question tells us the base of the ladder is 7 feet above the ground...
So, the TOTAL distance from the top of the ladder to the ground = 35√3 + 7
Answer: D
Cheers,
Brent
