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

It is currently 22 Sep 2014, 10:46

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Two missiles are launched simultaneously. Missile 1 launches

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
avatar
Joined: 22 Aug 2007
Posts: 573
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
Two missiles are launched simultaneously. Missile 1 launches [#permalink] New post 22 Oct 2007, 19:44
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Two missiles are launched simultaneously. Missile 1 launches at a speed of x miles per hour, increasing its speed by a factor of sqrt(x) every 10 minutes (so that after 10 minutes its speed is x*sqrt(x) , after 20 minutes its speed is x*sqrt(x)*x*sqrt(x) , and so forth. Missile 2 launches at a speed of y miles per hour, doubling its speed every 10 minutes. After 1 hour, is the speed of Missile 1 greater than that of Missile 2?

1) x=srt(y)
2) x>8

will post OA later.
VP
VP
avatar
Joined: 10 Jun 2007
Posts: 1467
Followers: 6

Kudos [?]: 102 [0], given: 0

GMAT Tests User
Re: DS_missiles launched [#permalink] New post 23 Oct 2007, 05:42
IrinaOK wrote:
Two missiles are launched simultaneously. Missile 1 launches at a speed of x miles per hour, increasing its speed by a factor of sqrt(x) every 10 minutes (so that after 10 minutes its speed is x*sqrt(x) , after 20 minutes its speed is x*sqrt(x)*x*sqrt(x) , and so forth. Missile 2 launches at a speed of y miles per hour, doubling its speed every 10 minutes. After 1 hour, is the speed of Missile 1 greater than that of Missile 2?

1) x=srt(y)
2) x>8

will post OA later.


C.

After one hour...
Missile 1 will be at x^4
Missile 2 will be at y^7

(1) if x=sqrt(y), then x^4 = y^2
So the question becomes: Is y^2 > y^7
Cannot be determined because we don't know if y<1 or y>1
INSUFFICIENT

(2) don't know anything about y
INSUFFICIENT

Together, you know that x>8
This means y = x^2 and since y is greater than 1, the question becomes:
Is y > y^5
Plug in some values of y...
SUFFICIENT
Intern
Intern
User avatar
Joined: 09 Oct 2007
Posts: 17
Followers: 0

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

Re: DS_missiles launched [#permalink] New post 23 Oct 2007, 06:32
IrinaOK wrote:
Two missiles are launched simultaneously. Missile 1 launches at a speed of x miles per hour, increasing its speed by a factor of sqrt(x) every 10 minutes (so that after 10 minutes its speed is x*sqrt(x) , after 20 minutes its speed is x*sqrt(x)*x*sqrt(x) , and so forth. Missile 2 launches at a speed of y miles per hour, doubling its speed every 10 minutes. After 1 hour, is the speed of Missile 1 greater than that of Missile 2?

1) x=srt(y)
2) x>8

will post OA later.


M1 in 1 hour: x*root(x) (10 min) *root(x) (20 min) *root(x) (30 min) *root(x) (40 min) *root(x) (50 min) *root(x) (1 hour).

Therefore, M1 will have speed = x*x*x*x = x^4.

M2 in 1 hour: y*2 (10 min) *2 (20 min) *2(30 min) *2(40 min) *2(50 min) *2 (1 hour) = y*2*2*2*2*2*2 = 64y.

We need to compare x^4 and 64 y.

1. x = root(y), x^4 = y^2.
y^2 and 32y. If y = 1, we have 1 and 32.
If y = 100, we have 10000 and 3200.
NOT Suff.

2. x>8. Let it be 9,
9^4 and 32y - Not suff.

3. Together.

y^2 and 32y, since x>8 and x = root (y), minimum y>64.

64^2 and 32*64.

Suff.

C.
Director
Director
avatar
Joined: 22 Aug 2007
Posts: 573
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
Re: DS_missiles launched [#permalink] New post 23 Oct 2007, 10:45
forgot x and y could be less than 1...

AO is C.

Thank you, guys!
Re: DS_missiles launched   [#permalink] 23 Oct 2007, 10:45
    Similar topics Author Replies Last post
Similar
Topics:
HBS Launches Campaign to Raise $1 Billion BlogBot 0 05 May 2014, 09:10
Experts publish their posts in the topic HBS Launches Campaign to Raise $1 Billion StacyBlackman 0 02 May 2014, 06:59
2 Experts publish their posts in the topic Critics contend that the new missile is a weapon whose Vercules 3 28 Mar 2013, 03:31
6 Experts publish their posts in the topic Two missiles are launched simultaneously. Missile 1 launches dvinoth86 3 23 Feb 2012, 19:22
Two projectiles are launched at the same moment cano 2 16 Sep 2010, 06:22
Display posts from previous: Sort by

Two missiles are launched simultaneously. Missile 1 launches

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.