Last visit was: 24 Apr 2026, 14:43 It is currently 24 Apr 2026, 14:43
Home
Messages
Tests
Schools
Events
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
Back to Forum
Create Topic
505-555 (Easy)|   Geometry|      
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 24 Apr 2026
Posts: 109,818
Own Kudos:
811,068
 [1]
Given Kudos: 105,873
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,818
Kudos: 811,068
 [1]
The volume of a cylindrical tank is directly proportional to the heigh 10 Dec 2017, 01:27
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

15% (low)

Question Stats:

87% (01:38) correct 13% (02:01) wrong based on 51 sessions

History

Date
Time
Result
Not Attempted Yet
The volume of a cylindrical tank is directly proportional to the height and the square of the radius of the tank. If a certain tank with a radius of 10 centimeters has a volume of 20,000 cubic centimeters, what is the volume, in cubic centimeters, of a tank of the same height with a radius of 15 centimeters?

(A) 300,000
(B) 45,000
(C) 30,000
(D) 15,000
(E) 4,500
ShowHide Answer
Official Answer
B
User avatar
exc4libur
User avatar
Joined: 24 Nov 2016
Last visit: 22 Mar 2022
Posts: 1,680
Own Kudos:
1,469
Given Kudos: 607
Location: United States
Posts: 1,680
Kudos: 1,469
The volume of a cylindrical tank is directly proportional to the heigh 10 Dec 2017, 04:46
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
The volume of a cylindrical tank is directly proportional to the height and the square of the radius of the tank. If a certain tank with a radius of 10 centimeters has a volume of 20,000 cubic centimeters, what is the volume, in cubic centimeters, of a tank of the same height with a radius of 15 centimeters?

(A) 300,000
(B) 45,000
(C) 30,000
(D) 15,000
(E) 4,500
Show more

\(\frac{10cm}{20,000cm^3}=\frac{15cm}{x}, 10cm*x=20,000cm^3*15, x=30,000cm^3\)

(C) is the answer.
avatar
rupak007
avatar
Joined: 27 Sep 2015
Last visit: 04 Oct 2018
Posts: 5
Own Kudos:
3
Given Kudos: 299
Products:
My Reviews
Posts: 5
Kudos: 3
The volume of a cylindrical tank is directly proportional to the heigh 10 Dec 2017, 05:06
Kudos
Add Kudos
Bookmarks
Bookmark this Post
V ∝ h*r^2 , where v= volume, h= height and r= radius of a cylinder .
So V= (hr^2 )k where k= constant .

So V1= 20000 cm^3= {h(10 cm)^2}k
V2= {h(15 cm)^2 }k

Dividing V1 by V2 we get,

V1/V2= (10/15)^2,
20000/V2= (2/3)^2=4/9,
So V2= 45000 cm^3,

(B) is the answer .



Sent from my iPhone using GMAT Club Forum
User avatar
generis
User avatar
Senior SC Moderator
Joined: 22 May 2016
Last visit: 18 Jun 2022
Posts: 5,258
Own Kudos:
37,728
Given Kudos: 9,464
Expert
Expert reply
Posts: 5,258
Kudos: 37,728
The volume of a cylindrical tank is directly proportional to the heigh 10 Dec 2017, 11:44
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
The volume of a cylindrical tank is directly proportional to the height and the square of the radius of the tank. If a certain tank with a radius of 10 centimeters has a volume of 20,000 cubic centimeters, what is the volume, in cubic centimeters, of a tank of the same height with a radius of 15 centimeters?

(A) 300,000
(B) 45,000
(C) 30,000
(D) 15,000
(E) 4,500
Show more
All measures are in centimeters; units omitted.

Direct proportion: When \(y\) increases, \(x\) increases

\(y = kx\)*, and \(\frac{y}{x}=k\)
\(k\) is the constant of proportionality: it does not change

Find \(k\) from the first scenario, and use \(k\) to find volume in the second scenario

Scenario 1 - find \(k\)
The volume of a cylindrical tank is directly proportional to the height and the square of the radius of the tank

\(V = (k)(h)(r^2)\) , and

\(\frac{V}{(h)(r^2)} = k\)

Height does not change. Remove it.
\(V_1 = 20,000\)
\(r_1 = 10\)

\(\frac{V_1}{(r_1)^2}= k\)

\(\frac{20,000}{(100)} = 200 = k\)

Scenario 2 - Use the same formula; and \(k\); and the given new radius to find new volume, \(V_2\)

\(k = 200\)
\(r_2 = 15\)
New volume, \(V_2\)?

\(\frac{V_2}{(r_2)^2} = k\)

\(\frac{V_2}{225} = 200\)

\(V_2 = (225)(200) = 45,000\)

Answer B

*Sometimes written \(y ∝ x\)
Moderators:
Bunuel
Math Expert
109818 posts
Krunaal
Tuck School Moderator
853 posts