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

 It is currently 15 Nov 2018, 15:17

### 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 GMAT Strategy Webinar

November 17, 2018

November 17, 2018

07:00 AM PST

09:00 AM PST

Nov. 17, 7 AM PST. Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
• ### GMATbuster's Weekly GMAT Quant Quiz # 9

November 17, 2018

November 17, 2018

09:00 AM PST

11:00 AM PST

Join the Quiz Saturday November 17th, 9 AM PST. The Quiz will last approximately 2 hours. Make sure you are on time or you will be at a disadvantage.

# A and B are 100 meters apart. A starts moving towards B at the same

Author Message
TAGS:

### Hide Tags

Manager
Joined: 04 Oct 2010
Posts: 60
GMAT 1: 720 Q48 V41
A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

Updated on: 21 Oct 2010, 22:40
1
A and B are 100 meters apart. A starts moving towards B at the same time B starts moving in the same direction away from A. If the Speed of B is 8 km/hr and that of A is 10 km/hr , how far will B have gone before he is overtaken?

Please post an explanation to solve the problem? Cant figure it out.

400 meters

_________________

---
Jimmy

Lifes battles dont always go,
To the stronger or faster man;
But sooner or later the man who wins,
Is the man who THINKS HE CAN .

KUDOS me if you feel my contribution has helped you.

Originally posted by jimmy86 on 19 Oct 2010, 03:21.
Last edited by jimmy86 on 21 Oct 2010, 22:40, edited 1 time in total.
Senior Manager
Joined: 04 Aug 2010
Posts: 305
Schools: Dartmouth College
Re: A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

19 Oct 2010, 09:04
4
2
jimmy86 wrote:
A and B are 100 meters apart. A starts moving towards B at the same time B starts moving in the same direction away from A. If the Speed of B is 8 km/hr and that of A is 10 km/hr , how far will B have gone before he is overtaken?

Please post an explanation to solve the problem? Cant figure it out.

First approach:

To catch up to B, A must travel 100 meters more than B.
Rate for A = 10000 m/hr, Rate for B = 8000 m/hr.
Distance A = r*t = 10000t
Distance B = r*t = 8000t
Thus, 10000t = 8000t + 100
2000t = 100
t = 100/2000 = 1/20 hours.
Distance for B = r*t = (1/20)*8000 = 400 meters.

Second approach:

Plug in the answer choices, which would represent the distance traveled by B.

B = 400 meters
Time for B = d/r = 400/8000 = 1/20 hours.
Distance for A = r*t = 10000*(1/20) = 500 meters.
A-B = 500-400 = 100 meters.
Since A travels 100 meters more than B, A will catch up to B. Thus, we would have found the correct answer.
_________________

GMAT and GRE Tutor
Over 1800 followers
GMATGuruNY@gmail.com
New York, NY
If you find one of my posts helpful, please take a moment to click on the "Kudos" icon.
Available for tutoring in NYC and long-distance.

##### General Discussion
Intern
Joined: 14 Oct 2010
Posts: 4
Re: A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

19 Oct 2010, 06:01
jimmy86 wrote:
A and B are 100 meters apart. A starts moving towards B at the same time B starts moving in the same direction away from A. If the Speed of B is 8 km/hr and that of A is 10 km/hr , how far will B have gone before he is overtaken?

Please post an explanation to solve the problem? Cant figure it out.

This question comes under the concept of Relative speed.
Given A & B are 100m apart and B is moving in the same direction away from A
Therefore their relative speed (ie., speed of B with respect to speed of A) is 2 km/hr
Carefully observe that speeds of A & B are given in Km/hr, we need to convert into m/s

distance = speed * time
100 = (2 * 5/18) * t
=> t = 180 sec

Therefore distance travelled by B in 180 sec is ( 8 * 180) = 1440 m or 1.4 KM
Manager
Joined: 04 Oct 2010
Posts: 60
GMAT 1: 720 Q48 V41
Re: A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

19 Oct 2010, 10:31
GMATGuruNY wrote:
jimmy86 wrote:
A and B are 100 meters apart. A starts moving towards B at the same time B starts moving in the same direction away from A. If the Speed of B is 8 km/hr and that of A is 10 km/hr , how far will B have gone before he is overtaken?

Please post an explanation to solve the problem? Cant figure it out.

First approach:

To catch up to B, A must travel 100 meters more than B.
Rate for A = 10000 m/hr, Rate for B = 8000 m/hr.
Distance A = r*t = 10000t
Distance B = r*t = 8000t
Thus, 10000t = 8000t + 100
2000t = 100
t = 100/2000 = 1/20 hours.
Distance for B = r*t = (1/20)*8000 = 400 meters.

Second approach:

Plug in the answer choices, which would represent the distance traveled by B.

B = 400 meters
Time for B = d/r = 400/8000 = 1/20 hours.
Distance for A = r*t = 10000*(1/20) = 500 meters.
A-B = 500-400 = 100 meters.
Since A travels 100 meters more than B, A will catch up to B. Thus, we would have found the correct answer.

Loved the way you explained the steps. Thanks a lot.
_________________

---
Jimmy

Lifes battles dont always go,
To the stronger or faster man;
But sooner or later the man who wins,
Is the man who THINKS HE CAN .

KUDOS me if you feel my contribution has helped you.

Senior Manager
Affiliations: SPG
Joined: 15 Nov 2006
Posts: 302
Re: A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

19 Jan 2011, 11:36
2

distance between A & B = 100m
difference of speed $$= 10-8 = 2km/h = \frac{100}{3}$$ m/min

time required to cover 100m $$= \frac{100*3}{100} = 3mins$$

distance traveled by B in 3mins $$= \frac{8000*3}{60}= 400m$$

VP
Joined: 07 Dec 2014
Posts: 1112
Re: A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

15 Feb 2016, 14:02
A gains 2km/hr on B
A needs to gain 100 meters=.1 k
.1 k/2 km/hr=1/20 hour
(1/20 hr)(8 km/hr)=.4 km=400 meters distance for B
Current Student
Joined: 03 Jan 2014
Posts: 64
Concentration: Strategy, Operations
GMAT 1: 720 Q46 V42
GPA: 3.86
WE: Information Technology (Consulting)
A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

10 Mar 2016, 20:16
1
Since they will be traveling for the same amount of time I set the two times equal to one another (x is the distance for B):

Distance covered by A: x + 100
Distance covered by B: x

$$(x + 100) / 10 = x / 8$$ --> solve for x. $$x = 400$$
Intern
Status: One more try
Joined: 01 Feb 2015
Posts: 43
Location: India
Concentration: General Management, Economics
WE: Corporate Finance (Commercial Banking)
Re: A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

17 May 2016, 07:40
jimmy86 wrote:
A and B are 100 meters apart. A starts moving towards B at the same time B starts moving in the same direction away from A. If the Speed of B is 8 km/hr and that of A is 10 km/hr , how far will B have gone before he is overtaken?

Please post an explanation to solve the problem? Can`t figure it out.

400 meters

3 mins to overtake
400 metres
_________________

Believe you can and you are halfway there-Theodore Roosevelt

Non-Human User
Joined: 09 Sep 2013
Posts: 8772
Re: A and B are 100 meters apart. A starts moving towards B at the same  [#permalink]

### Show Tags

22 Jul 2018, 17:42
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.
_________________
Re: A and B are 100 meters apart. A starts moving towards B at the same &nbs [#permalink] 22 Jul 2018, 17:42
Display posts from previous: Sort by