NEW HERE? LEARN MORE
closeclose
It is currently 27 Sep 2023, 00:25
Register
GMAT Club Tests
Decision Tracker
My Rewards
New posts
New comers' posts

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel

Find the ratio of areas of the Triangle ABC and ADB

11 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
User avatar
B
JusTLucK04
Retired Moderator
Joined: 17 Sep 2013
Posts: 284
Concentration: Strategy, General Management
Schools: Kelley '18 (M) Mendoza '18 (WL) Duke '18 (D) Goizueta '18 (D) ISB '17 (D) Owen '17 (I)
GMAT 1: 730 Q51 V38
WE:Analyst (Consulting)
GMAT ToolKit User Reviews Badge
Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  Updated on: 26 Apr 2014, 00:19
7
Kudos
11
Bookmarks
Quiz Dashboard Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
00:00
A
B
C
D
E

Difficulty:

65% (hard)

Question Stats:

57% (01:40) correct 43% (01:56) wrong based on 206 sessions

Hide Show timer Statistics

Find the ratio of areas of the triangle ADB and ABC. If BD:DC = 3:5

A. 3:5
B. 9:25
C. 3:8
D. 5:9
E. 9:16

Kudos If you liked the Question
ShowHide Answer
Official Answer
Official Answer and Stats are available only to registered users. Register/Login.

Attachments

Untitled.png
Untitled.png [ 3.55 KiB | Viewed 6479 times ]


Originally posted by JusTLucK04 on 25 Apr 2014, 01:30.
Last edited by JusTLucK04 on 26 Apr 2014, 00:19, edited 5 times in total.
Quiz Dashboard Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 89535
CAT Tests Forum Quiz Mode
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  06 May 2014, 09:22
2
Kudos
2
Bookmarks
Expert Reply
JusTLucK04 wrote:

Find the ratio of areas of the triangle ADB and ABC. If BD:DC = 3:5

A. 3:5
B. 9:25
C. 3:8
D. 5:9
E. 9:16

Kudos If you liked the Question


BD:DC = 3:5 --> BD:(BD+DC) = 3:(3+5) --> BD:BC = 3:8.

The area of triangle ADB = 1/2*(height from A to DB)*(DB).
The area of triangle ABC = 1/2*(height from A to BC)*(BC).

Notice that (height from A to DB) = (height from A to BC).

Therefore the ration of the areas of ADB and ABC = DB:BC = 3:8.

Answer: C.
_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
User avatar
P
sunita123
Manager
Manager
Joined: 13 Oct 2013
Posts: 120
Concentration: Strategy, Entrepreneurship
GMAT ToolKit User
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  06 May 2014, 12:03
Hi Bunuel,
Excuse me if i do not have clear concept in Geometry.

So I do not understand how below statement is true.

(height from A to DB) = (height from A to BC).

Thanks for your help.


Bunuel wrote:
JusTLucK04 wrote:

Find the ratio of areas of the triangle ADB and ABC. If BD:DC = 3:5

A. 3:5
B. 9:25
C. 3:8
D. 5:9
E. 9:16

Kudos If you liked the Question


BD:DC = 3:5 --> BD:(BD+DC) = 3:(3+5) --> BD:BC = 3:8.

The area of triangle ADB = 1/2*(height from A to DB)*(DB).
The area of triangle ABC = 1/2*(height from A to BC)*(BC).

Notice that (height from A to DB) = (height from A to BC).

Therefore the ration of the areas of ADB and ABC = DB:BC = 3:8.

Answer: C.
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 89535
CAT Tests Forum Quiz Mode
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  07 May 2014, 02:08
Expert Reply
sunita123 wrote:
Hi Bunuel,
Excuse me if i do not have clear concept in Geometry.

So I do not understand how below statement is true.

(height from A to DB) = (height from A to BC).

Thanks for your help.


Bunuel wrote:
JusTLucK04 wrote:

Find the ratio of areas of the triangle ADB and ABC. If BD:DC = 3:5

A. 3:5
B. 9:25
C. 3:8
D. 5:9
E. 9:16

Kudos If you liked the Question


BD:DC = 3:5 --> BD:(BD+DC) = 3:(3+5) --> BD:BC = 3:8.

The area of triangle ADB = 1/2*(height from A to DB)*(DB).
The area of triangle ABC = 1/2*(height from A to BC)*(BC).

Notice that (height from A to DB) = (height from A to BC).

Therefore the ration of the areas of ADB and ABC = DB:BC = 3:8.

Answer: C.


Line segments DB and BC are on the same line, thus the perpendicular from point A to DB is the same as the perpendicular from point A to BC.
_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
User avatar
ronr34
Senior Manager
Senior Manager
Joined: 08 Apr 2012
Posts: 267
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  10 Jun 2014, 15:02
Bunuel wrote:
JusTLucK04 wrote:

Find the ratio of areas of the triangle ADB and ABC. If BD:DC = 3:5

A. 3:5
B. 9:25
C. 3:8
D. 5:9
E. 9:16

Kudos If you liked the Question


BD:DC = 3:5 --> BD:(BD+DC) = 3:(3+5) --> BD:BC = 3:8.

The area of triangle ADB = 1/2*(height from A to DB)*(DB).
The area of triangle ABC = 1/2*(height from A to BC)*(BC).

Notice that (height from A to DB) = (height from A to BC).

Therefore the ration of the areas of ADB and ABC = DB:BC = 3:8.

Answer: C.

Hi Bunuel,

in a lot of questions, we get to the bottom line of: ratio of area = (ratio of side)^2.

Is this not true? Is this true only in specific cases?
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 89535
CAT Tests Forum Quiz Mode
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  11 Jun 2014, 14:07
1
Bookmarks
Expert Reply
ronr34 wrote:
Bunuel wrote:
JusTLucK04 wrote:

Find the ratio of areas of the triangle ADB and ABC. If BD:DC = 3:5

A. 3:5
B. 9:25
C. 3:8
D. 5:9
E. 9:16

Kudos If you liked the Question


BD:DC = 3:5 --> BD:(BD+DC) = 3:(3+5) --> BD:BC = 3:8.

The area of triangle ADB = 1/2*(height from A to DB)*(DB).
The area of triangle ABC = 1/2*(height from A to BC)*(BC).

Notice that (height from A to DB) = (height from A to BC).

Therefore the ration of the areas of ADB and ABC = DB:BC = 3:8.

Answer: C.

Hi Bunuel,

in a lot of questions, we get to the bottom line of: ratio of area = (ratio of side)^2.

Is this not true? Is this true only in specific cases?


This is true for similar triangles.

If two similar triangles have sides in the ratio \(\frac{x}{y}\), then their areas are in the ratio \(\frac{x^2}{y^2}\).
OR in another way: in two similar triangles, the ratio of their areas is the square of the ratio of their sides: \(\frac{AREA}{area}=\frac{SIDE^2}{side^2}\).
_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
User avatar
P
mvictor
Board of Directors
Joined: 17 Jul 2014
Posts: 2180
Location: United States (IL)
Concentration: Finance, Economics
Schools: Stanford '20 (WD)
GMAT 1: 650 Q49 V30
GPA: 3.92
WE:General Management (Transportation)
GMAT ToolKit User Reviews Badge
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  20 Apr 2016, 19:27
oh damn..i was on my laptop..and the screen is small...i did not see the image..was going crazy to identify how the triangle might look like...
BD= suppose 3x
DC = 5x
BC=8x
the height is the same for the both triangles, so basically, we are asked for the ratio of the bases. BC/BD = 3x/8x = 3/8
User avatar
G
CEdward
VP
VP
Joined: 11 Aug 2020
Posts: 1297
Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  24 Mar 2021, 14:31
Bunuel

I am confused. So this current problem, the triangles are not similar?
_________________
"Do not pray for an easy life, pray for the strength to endure a difficult one." - Bruce Lee
Signature Read More
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 89535
CAT Tests Forum Quiz Mode
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  24 Mar 2021, 14:38
Expert Reply
CEdward wrote:
Bunuel

I am confused. So this current problem, the triangles are not similar?


No, there are no similar triangles in the figure.
_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
User avatar
G
rsrighosh
Manager
Manager
Joined: 13 Jun 2019
Posts: 205
GMAT 1: 490 Q42 V17
GMAT 2: 550 Q39 V27
GMAT 3: 630 Q49 V27
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  25 Mar 2021, 10:49
I too fell in the trap thinking that these are similar triangles.... and I was making a mistake of drawing the 2 perpendicular lines 1 from D and the other from C

But perpendicular from A makes more sense. Answer is indeed 3/8

Bunuel Thanks a lot
_________________

Shrekey


Need help desperately to know your strategy in keeping mind steady during GMAT Exam.
Please help in the below post.
https://gmatclub.com/forum/struggling-in-timed-test-like-gmat-how-to-keep-mind-calm-353103.html
Signature Read More
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 29493
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink] New post  25 Dec 2022, 12:42
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources
Signature Read More
GMAT Club Bot
gmatclubot
Re: Find the ratio of areas of the Triangle ABC and ADB [#permalink]
25 Dec 2022, 12:42
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderators:
Bunuel
Math Expert
89534 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3135 posts

cron

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions