Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 04 May 2015, 08:28

### 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 June
Open Detailed Calendar

# The price of an automobile decreased m percent between 2010

Author Message
TAGS:
Manager
Status: Never ever give up on yourself.Period.
Joined: 23 Aug 2012
Posts: 147
Location: India
Concentration: Finance, Human Resources
Schools: MBS '17 (A)
GMAT 1: 570 Q47 V21
GMAT 2: 690 Q50 V33
GPA: 3.5
WE: Information Technology (Investment Banking)
Followers: 8

Kudos [?]: 147 [0], given: 35

The price of an automobile decreased m percent between 2010 [#permalink]  14 Dec 2012, 08:19
2
This post was
BOOKMARKED
00:00

Difficulty:

55% (hard)

Question Stats:

68% (02:34) correct 32% (03:13) wrong based on 40 sessions
The price of an automobile decreased m percent between 2010 and 2011 and then increased n percent between 2011 and 2012. Was the price of the automobile lower in 2010 than in 2012?

(1) m < n
(2) mn < 100n – 100m
[Reveal] Spoiler: OA

_________________

Don't give up on yourself ever. Period.
Beat it, no one wants to be defeated (My journey from 570 to 690) : beat-it-no-one-wants-to-be-defeated-journey-570-to-149968.html

Math Expert
Joined: 02 Sep 2009
Posts: 27215
Followers: 4225

Kudos [?]: 40984 [1] , given: 5654

Re: The price of an automobile decreased m percent between 2010 [#permalink]  14 Dec 2012, 08:51
1
KUDOS
Expert's post
The price of an automobile decreased m percent between 2010 and 2011 and then increased n percent between 2011 and 2012. Was the price of the automobile lower in 2010 than in 2012?

The price in 2010 - $$p$$;
The price in 2011 - $$p*(1-\frac{m}{100})$$;
The price in 2012 - $$p*(1-\frac{m}{100})*(1+\frac{n}{100})$$;

Question: is $$p<p*(1-\frac{m}{100})*(1+\frac{n}{100})$$? --> is $$1<(1-\frac{m}{100})*(1+\frac{n}{100})$$? --> is $$100n-100m>mn$$?

(1) m < n. Not sufficient.
(2) mn < 100n – 100m. Directly answers the question. Sufficient.

Identical question from OG to practice: the-annual-rent-collected-by-a-corporation-from-a-certain-89184.html
_________________
Moderator
Joined: 01 Sep 2010
Posts: 2587
Followers: 424

Kudos [?]: 3371 [0], given: 720

Re: The price of an automobile decreased m percent between 2010 [#permalink]  14 Dec 2012, 11:14
Expert's post
1 ) is clearly insufficient

2) $$MN$$ $$<$$ $$100 N - 100 M$$

here a faster approach is simply pickying a %. for instance: first we have a decrease so we could have 0.8 % (decrease by 20%) the an increse %, for instance 1.2 % (increase by 20 %).

Always the LHS is not smaller than the RHS

$$0.96 < 0.4$$ The answer, even with other numbers will be always NO. So is sufficient

_________________
BSchool Forum Moderator
Joined: 27 Aug 2012
Posts: 1153
Followers: 97

Kudos [?]: 728 [0], given: 121

Re: The price of an automobile decreased m percent between 2010 [#permalink]  13 Sep 2013, 00:07
Expert's post
Bunuel wrote:
The price of an automobile decreased m percent between 2010 and 2011 and then increased n percent between 2011 and 2012. Was the price of the automobile lower in 2010 than in 2012?

The price in 2010 - $$p$$;
The price in 2011 - $$p*(1-\frac{m}{100})$$;
The price in 2012 - $$p*(1-\frac{m}{100})*(1+\frac{n}{100})$$;

Question: is $$p<p*(1-\frac{m}{100})*(1+\frac{n}{100})$$? --> is $$1<(1-\frac{m}{100})*(1+\frac{n}{100})$$? --> is $$100n-100m>mn$$?

(1) m < n. Not sufficient.
(2) mn < 100n – 100m. Directly answers the question. Sufficient.

Identical question from OG to practice: the-annual-rent-collected-by-a-corporation-from-a-certain-89184.html

Hi Bunuel,
How we can say that Stat.1 is NOT sufficient even without plugging in values? I'm getting it clear by plugging values but what I'd like to know is there any faster way to determine the sufficiency of Stat.1 from the inequality?

_________________
Re: The price of an automobile decreased m percent between 2010   [#permalink] 13 Sep 2013, 00:07
Similar topics Replies Last post
Similar
Topics:
5 Decreasing the original price of an item by 25% and then 5 04 Mar 2013, 07:13
Percent Increase/decrease help!!! 1 04 May 2011, 21:37
The price was increased by x % and then decreased by y %. Is 6 02 Mar 2008, 03:22
For most consumers, the price of automobile insurance 3 24 Mar 2006, 17:53
For most consumers, the price of automobile insurance 15 21 Sep 2005, 21:47
Display posts from previous: Sort by