Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 27 May 2017, 02:13

### 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

# A and B ran, at their respective constant rates, a race of 480 m. In

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 38909
Followers: 7741

Kudos [?]: 106277 [2] , given: 11618

A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

11 Oct 2009, 18:14
2
KUDOS
Expert's post
6
This post was
BOOKMARKED
00:00

Difficulty:

75% (hard)

Question Stats:

63% (03:38) correct 37% (03:33) wrong based on 72 sessions

### HideShow timer Statistics

A and B ran, at their respective constant rates, a race of 480 m. In the first heat, A gives B a head start of 48 m and beats him by 1/10th of a minute. In the second heat, A gives B a head start of 144 m and is beaten by 1/30th of a minute. What is B’s speed in m/s?

(A) 12
(B) 14
(C) 16
(D) 18
(E) 20

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-and-b-ran-at-their-respective-constant-rates-a-race-of-480-m-in-106921.html
[Reveal] Spoiler: OA

_________________
Intern
Joined: 07 Oct 2009
Posts: 19
Followers: 0

Kudos [?]: 11 [0], given: 0

Re: A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

12 Oct 2009, 03:55
solve these two simultaneous equations

432/b - 480/a = 6 - I
480/a - 336/b = 2 - II

I - II gives you
so we get 96/b = 8
therefore b = 12

Senior Manager
Status: Yeah well whatever.
Joined: 18 Sep 2009
Posts: 343
Location: United States
GMAT 1: 660 Q42 V39
GMAT 2: 730 Q48 V42
GPA: 3.49
WE: Analyst (Insurance)
Followers: 5

Kudos [?]: 74 [0], given: 17

Re: A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

12 Oct 2009, 07:37
_________________

He that is in me > he that is in the world. - source 1 John 4:4

Math Expert
Joined: 02 Sep 2009
Posts: 38909
Followers: 7741

Kudos [?]: 106277 [0], given: 11618

Re: A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

12 Oct 2009, 09:26
Set of Tough & tricky questions is now combined in one thread: tough-tricky-set-of-problms-85211.html

You can continue discussions and see the solutions there.
_________________
Intern
Joined: 07 Oct 2009
Posts: 19
Followers: 0

Kudos [?]: 11 [0], given: 0

Re: A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

12 Oct 2009, 09:35
1/10th of a minute = 6 seconds
Similarly 1/30th of a minute is 2 seconds
Also in first race A reaches before B whereas in second race B reaches before. Hence the order of equations
VP
Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 1334
Followers: 17

Kudos [?]: 254 [0], given: 10

Re: A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

09 May 2011, 03:39
432/Sb -480/Sa = 6

480/Sa - 336/Sb = 2

gives Sb = 12
_________________

Visit -- http://www.sustainable-sphere.com/
Promote Green Business,Sustainable Living and Green Earth !!

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 15477
Followers: 651

Kudos [?]: 209 [0], given: 0

Re: A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

24 Jul 2016, 06:07
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 38909
Followers: 7741

Kudos [?]: 106277 [1] , given: 11618

Re: A and B ran, at their respective constant rates, a race of 480 m. In [#permalink]

### Show Tags

24 Jul 2016, 08:18
1
KUDOS
Expert's post
2
This post was
BOOKMARKED
Bunuel wrote:
A and B ran, at their respective constant rates, a race of 480 m. In the first heat, A gives B a head start of 48 m and beats him by 1/10th of a minute. In the second heat, A gives B a head start of 144 m and is beaten by 1/30th of a minute. What is B’s speed in m/s?

(A) 12
(B) 14
(C) 16
(D) 18
(E) 20

Let $$x$$ be the speed of B.

Write the equation:

(480-48)/x (time of B for first heat) - 6 (seconds, time B lost to A first heat) = TIME OF A (in both heats A runs with constant rate, so the time for first and second heats are the same)=(480-144)/x (time of B for second heat) + 2 (seconds, time B won to A second heat)

$$\frac{480-48}{x}-6=\frac{480-144}{x}+2$$ --> $$x=12$$.

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-and-b-ran-at-their-respective-constant-rates-a-race-of-480-m-in-106921.html
_________________
Re: A and B ran, at their respective constant rates, a race of 480 m. In   [#permalink] 24 Jul 2016, 08:18
Similar topics Replies Last post
Similar
Topics:
126 Working simultaneously at their respective constant rates, M 29 22 Apr 2017, 16:33
65 A and B ran, at their respective constant rates, a race of 480 m. In 21 27 Feb 2017, 08:55
18 A and B ran, at their respective constant rates, a race of 4 13 29 Oct 2014, 21:37
164 Running at their respective constant rates, machine X takes 42 08 Jan 2017, 17:58
166 Pumps A, B, and C operate at their respective constant rates. Pumps A 23 08 Feb 2017, 11:20
Display posts from previous: Sort by