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

It is currently 16 Aug 2018, 01:14

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.

Close

Request Expert Reply

Confirm Cancel

How many computers did Michael, a salesman for the computer

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Manager
Manager
avatar
Joined: 21 Sep 2012
Posts: 227
How many computers did Michael, a salesman for the computer  [#permalink]

Show Tags

New post 01 Nov 2012, 02:12
2
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

66% (02:00) correct 34% (01:56) wrong based on 156 sessions

HideShow timer Statistics

How many computers did Michael, a salesman for the computer company Digital Electronics Labs, sell this past year that had more than 4GB of RAM and the Microsoft Windows XP operating system? (Michael sold no computers with exactly 4GB of RAM)

(1) 40% of the 200 total computers that Michael sold had XP and less than 4GB of RAM; these computers represent 80% of the total computers that Michael sold with XP.
(2) 50% of the 200 total computers that Michael sold had XP. Of the computers that Michael sold without XP, half had more than 4GB of RAM while the other half had less than 4GB of RAM.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47920
Re: How many computers did Michael, a salesman for the computer  [#permalink]

Show Tags

New post 01 Nov 2012, 09:02
2
How many computers did Michael, a salesman for the computer company Digital Electronics Labs, sell this past year that had more than 4GB of RAM and the Microsoft Windows XP operating system? (Michael sold no computers with exactly 4GB of RAM)

We need to determine the number of computers sold with XP AND more than 4GB of RAM.

(1) 40% of the 200 total computers that Michael sold had XP and less than 4GB of RAM; these computers represent 80% of the total computers that Michael sold with XP.

0.4*200=80 computers had XP and less than 4GB of RAM. Since these 80 computers represent 80% of the computers with XP, then Michael sold 100 computers with XP. Since, we already know that 80 computers had XP and less than 4GB of RAM, then the rest of the computers with XP had more than 4GB of RAM, thus 100-80=20 computers had XP and more than 4GB of RAM. Sufficient.

(2) 50% of the 200 total computers that Michael sold had XP. Of the computers that Michael sold without XP, half had more than 4GB of RAM while the other half had less than 4GB of RAM

0.5*200=100 computers had XP and 100 did not. The second part of the statement gives info only about the computers without XP, thus it's basically useless for us. Not sufficient.

Answer: A.

Hope it's clear.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 6524
Re: How many computers did Michael, a salesman for the computer  [#permalink]

Show Tags

New post 23 Dec 2017, 09:03
nelz007 wrote:
How many computers did Michael, a salesman for the computer company Digital Electronics Labs, sell this past year that had more than 4GB of RAM and the Microsoft Windows XP operating system? (Michael sold no computers with exactly 4GB of RAM)

(1) 40% of the 200 total computers that Michael sold had XP and less than 4GB of RAM; these computers represent 80% of the total computers that Michael sold with XP.
(2) 50% of the 200 total computers that Michael sold had XP. Of the computers that Michael sold without XP, half had more than 4GB of RAM while the other half had less than 4GB of RAM.




so we are looking for COMPUTERS sold that had>4GB RAM and XP OS..

(1) 40% of the 200 total computers that Michael sold had XP and less than 4GB of RAM; these computers represent 80% of the total computers that Michael sold with XP.
Total computers sold = 200,
40% of it so \(\frac{40}{100}*200=80\) had <4GB and XP os
80% of Computers sold with XP os = 80, so computers sold with XP =\(80*\frac{100}{80}=100\)
so BOTH XP and >4GB = 100-80=20
suff

(2) 50% of the 200 total computers that Michael sold had XP. Of the computers that Michael sold without XP, half had more than 4GB of RAM while the other half had less than 4GB of RAM.
clearly insuff

A
_________________

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

Re: How many computers did Michael, a salesman for the computer &nbs [#permalink] 23 Dec 2017, 09:03
Display posts from previous: Sort by

How many computers did Michael, a salesman for the computer

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.