GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 16 Nov 2018, 06:00

### 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

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

## Events & Promotions

###### Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
• ### Free GMAT Strategy Webinar

November 17, 2018

November 17, 2018

07:00 AM PST

09:00 AM PST

Nov. 17, 7 AM PST. Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
• ### GMATbuster's Weekly GMAT Quant Quiz # 9

November 17, 2018

November 17, 2018

09:00 AM PST

11:00 AM PST

Join the Quiz Saturday November 17th, 9 AM PST. The Quiz will last approximately 2 hours. Make sure you are on time or you will be at a disadvantage.

# Consider the formula H = 2a^3/b. If a is doubled and b is increased

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 50617
Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

03 Dec 2015, 05:30
00:00

Difficulty:

25% (medium)

Question Stats:

70% (01:05) correct 30% (02:09) wrong based on 121 sessions

### HideShow timer Statistics

Consider the formula $$H = \frac{2a^3}{b}$$. If a is doubled and b is increased by a factor of 4, by what factor is H increased?

A. 2
B. 4
C. 6
D. 8
E. 16

_________________
Director
Joined: 20 Feb 2015
Posts: 796
Concentration: Strategy, General Management
Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

03 Dec 2015, 05:43
after applying ----------- stated in question

H' = 2*(2a)^3/4b
H' = 2*8a^3/4b
H' = 8/4(H)
H' = 2 H
Thus A
Intern
Status: You think you cannot?? Rethink & repeat until its done - Abdul Rauf Liaqat
Joined: 09 Nov 2015
Posts: 20
Location: Pakistan
Concentration: Entrepreneurship, Strategy
GMAT 1: 460 Q45 V11
GPA: 3.03
WE: Operations (Telecommunications)
Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

03 Dec 2015, 06:29
H = (2a^3)/b
if a is doubled and b is incresead by factor of 4 then equation becomes
H = [2*(2a)^3] / 4b
H = 16a^3 / 4b
H = 4a^3 / b

Initially H = (2a^3) / b, Now H = (4a^3) / b which means H has been increased by a factor of 2.

_________________

+1 Kudos will be appreciated if you find this post helpful
Take up one idea. Make that one idea your life - think of it, dream of it, live on that idea. Let the brain, muscles, nerves, every part of your body, be full of that idea, and just leave every other idea alone. This is the way to success - Swami Vivekananda

Intern
Joined: 09 Sep 2015
Posts: 32
Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

03 Dec 2015, 07:01
A..

h= 2 (8) A^3/(4) B

HENCE A
Intern
Joined: 23 Nov 2016
Posts: 18
Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

06 Sep 2018, 17:18
The question formation is wrong, when we are saying that "b" is increased by a factor of 4 ,this means that my new b will be b+4k form. If the question formed was b is increased to a factor of 4 then b will be 4k. If the answer to the question has to be A.2 then b must be written simply become 4 times.
Manager
Joined: 18 Apr 2018
Posts: 69
Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

07 Sep 2018, 05:31
I agree I also interpreted the question as b+4b...I would like to know what is wrong with my thinking...thanks.

Posted from my mobile device
Intern
Joined: 27 Feb 2018
Posts: 48
Location: India
Concentration: Strategy, Entrepreneurship
GMAT 1: 650 Q48 V32
GPA: 3.86
Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

08 Sep 2018, 03:58
Bunuel wrote:
Consider the formula $$H = \frac{2a^3}{b}$$. If a is doubled and b is increased by a factor of 4, by what factor is H increased?

A. 2
B. 4
C. 6
D. 8
E. 16

Hi Bunel, b is increased by factor k means bk + k or bk ?

was stuck by this for some time
_________________

Stay in the fight. Die another day!

Manager
Joined: 07 Aug 2018
Posts: 75
Location: Croatia (Hrvatska)
GMAT 1: 560 Q39 V28
Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased  [#permalink]

### Show Tags

09 Sep 2018, 02:19
H=$$\frac{2a^3}{b}$$ --> H= $$\frac{a^3}{b}$$*2

The increase results in the following equation:

$$\frac{2*(2a)^3}{4b}$$ --> $$\frac{16a^3}{4b}$$ --> $$\frac{4a^3}{b}$$ --> $$\frac{a^3}{b}$$*4
2*2=4 Hence, A.
_________________

Flashcards Quant + Verbal:https://gmatclub.com/forum/gmat-flashcards-108651.html
Thursdays with Ron:https://gmatclub.com/forum/manhattan-s-thursdays-with-ron-consolidated-video-index-223612.html#p2138753

Re: Consider the formula H = 2a^3/b. If a is doubled and b is increased &nbs [#permalink] 09 Sep 2018, 02:19
Display posts from previous: Sort by