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

 It is currently 17 Nov 2018, 11:32

Join here

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 Quant Workshop by e-GMAT!

November 18, 2018

November 18, 2018

07:00 AM PST

09:00 AM PST

Get personalized insights on how to achieve your Target Quant Score. November 18th, 7 AM PST
• How to QUICKLY Solve GMAT Questions - GMAT Club Chat

November 20, 2018

November 20, 2018

09:00 AM PST

10:00 AM PST

The reward for signing up with the registration form and attending the chat is: 6 free examPAL quizzes to practice your new skills after the chat.

If a, b, c are positive numbers, is c equal to b percent more than a?

Author Message
TAGS:

Hide Tags

DS Forum Moderator
Joined: 21 Aug 2013
Posts: 1365
Location: India
If a, b, c are positive numbers, is c equal to b percent more than a?  [#permalink]

Show Tags

23 Jul 2018, 20:24
3
00:00

Difficulty:

45% (medium)

Question Stats:

64% (02:15) correct 36% (02:34) wrong based on 53 sessions

HideShow timer Statistics

If a, b, c are positive numbers, is c equal to b percent more than a?

(1) a is ab/c % less than c.

(2) ab/(c-a) = 100
MBA Section Director
Affiliations: GMATClub
Joined: 22 May 2017
Posts: 995
Concentration: Nonprofit
GPA: 4
WE: Engineering (Computer Software)
Re: If a, b, c are positive numbers, is c equal to b percent more than a?  [#permalink]

Show Tags

23 Jul 2018, 21:34
1
To find whether c is equal to b percent more than a

=> To find c = $$a * (\frac{b}{100} + 1)$$

=> To find c = $$\frac{ab + 100a}{100}$$

=> To find 100c = ab + 100a

Statement 1

a is $$\frac{ab}{c}$$ % less than c

=> a = c * $$(1 - \frac{ab}{c} * \frac{1}{100})$$

=>a = $$\frac{100c^2 - abc}{100c}$$

=> 100ac = $$100c^2 - abc$$

=> 100a = 100c - ab

=> 100c = ab + 100a

Statement 1 is sufficient

Statement 2

$$\frac{ab}{c - a}$$ = 100

=> 100(c - a) = ab

=> 100c - 100a = ab

=> 100c = ab + 100a

Statement 2 is sufficient

Hence option D
_________________

If you like my post press kudos +1

New project wSTAT(which Schools To Apply To?)

New - RC Butler - 2 RC's everyday

Math Expert
Joined: 02 Aug 2009
Posts: 7036
If a, b, c are positive numbers, is c equal to b percent more than a?  [#permalink]

Show Tags

23 Jul 2018, 21:48
amanvermagmat wrote:
If a, b, c are positive numbers, is c equal to b percent more than a?

(1) a is ab/c % less than c.

(2) ab/(c-a) = 100

It is all about forming equations and getting them in a form similar to given in the statements..
is c equal to b percent more than a?
means
$$c=\frac{100+b}{100}*a=a+\frac{ab}{100}$$

let us see the statements:-

(1) a is ab/c % less than c.
$$a=(1-\frac{ab}{100c})*c=c-\frac{ab}{100}...........c=a+\frac{b}{100}$$
same as main statement
sufficient

(2) ab/(c-a) = 100
$$\frac{ab}{(c-a)} = 100....................ab=100(c-a)..............c-a=\frac{ab}{100}.............c=a+\frac{ab}{100}$$
sufficient

D
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor

If a, b, c are positive numbers, is c equal to b percent more than a? &nbs [#permalink] 23 Jul 2018, 21:48
Display posts from previous: Sort by