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

 It is currently 21 Sep 2019, 06:22

### 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

# While on a straight road, Car X and Car Y are traveling at

Author Message
TAGS:

### Hide Tags

Manager
Status: Back to (GMAT) Times Square!!!
Joined: 15 Aug 2011
Posts: 117
Location: United States (IL)
GMAT 1: 650 Q49 V30
WE: Information Technology (Computer Software)
While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

Updated on: 07 Dec 2012, 10:38
6
1
30
00:00

Difficulty:

25% (medium)

Question Stats:

73% (01:23) correct 27% (01:48) wrong based on 1419 sessions

### HideShow timer Statistics

While on a straight road, Car X and Car Y are traveling at different constant rates. If Car X is now 1 mile ahead of Car Y, how many minutes from now will Car X be 2 miles ahead of Car Y ?

(1) Car X is traveling at 50 miles per hour and Car Y is traveling at 40 miles per hour.
(2) Three minutes ago Car X was 1/2 mile ahead of Car Y.

_________________
Working towards a goal...
V.

Originally posted by vix on 17 Mar 2012, 18:44.
Last edited by Bunuel on 07 Dec 2012, 10:38, edited 1 time in total.
Renamed the topic and edited the question.
Math Expert
Joined: 02 Sep 2009
Posts: 58137
Re: While on a straight road, car X and car Y are traveling at  [#permalink]

### Show Tags

18 Mar 2012, 07:21
4
8
While on a straight road, Car X and Car Y are traveling at different constant rates. If Car X is now 1 mile ahead of Car Y, how many minutes from now will Car X be 2 miles ahead of Car Y ?

(1) Car X is traveling at 50 miles per hour and Car Y is traveling at 40 miles per hour --> since we have the rates of both cars and the distance between them we can calculate any other question regarding them. Sufficient.

(2) Three minutes ago Car X was 1/2 mile ahead of Car Y --> car X gains 1/2 mile in every 3 minutes (since now it's 1 mile ahead), hence it'll gain additional 1 mile in next 6 minutes. Sufficient.

_________________
Manager
Status: And the Prep starts again...
Joined: 03 Aug 2010
Posts: 100
Re: GMAT Paper Tests 1  [#permalink]

### Show Tags

17 Mar 2012, 21:22
6
4
A follows B, Time to catchup = (Distance between A and B)/(SA - SB)

A)
SA - SB is the relative speed = 50-40=10 m/hr
Distance between A and B = 2-1 = 1.

Therefore, Time to catchup = 1/10 hours = 0.1*60 minutes = 6 mintues

Sufficient.

B)
3 minutes for 1/2 mile
Therefore 1 mile will be 6 minutes

Sufficient

Thus D.
_________________
My First Blog on my GMAT Journey

Arise, Awake and Stop not till the goal is reached
##### General Discussion
Senior Manager
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 427
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Re: While on a straight road, car X and car Y are traveling at  [#permalink]

### Show Tags

11 Nov 2012, 02:06
3
1
ok.. i just figured out..

1)

relative speed: 10 miles/ hour = 1/6 miles / min
distance to be covered: 1 mile.

time taken : 1/(1/6) = 6 mins..

2)
find the rate :
distance : 1/2 mile
time taken: 3 mins

rate: 1/6 miles / min

now,
distance=1 mile
rate : 1/6 miles/ min

so time: 6 mins

hope it helps! ( Bunuel's statement )
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.

Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595

My GMAT Journey : http://gmatclub.com/forum/end-of-my-gmat-journey-149328.html#p1197992
Senior Manager
Joined: 13 May 2013
Posts: 410
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

01 Aug 2013, 13:00
3
While on a straight road, Car X and Car Y are traveling at different constant rates. If Car X is now 1 mile ahead of Car Y, how many minutes from now will Car X be 2 miles ahead of Car Y ?

Car X is traveling at a greater speed/rate than Y.

(1) Car X is traveling at 50 miles per hour and Car Y is traveling at 40 miles per hour.

Car X is traveling at 5/6 miles/minute.
Car Y is traveling at 4/6 miles/minute.

Every minute, Car X moves away from car Y at a rate of (5/6) - (4/6) = 1/6 miles. Therefore, car X will have moved an additional mile away from car Y in six minutes.
SUFFICIENT

(2) Three minutes ago Car X was 1/2 mile ahead of Car Y.
In three minutes, car X managed to move 1/2 mile further away from Y. Because both cars were moving at constant rates, car x would have moved away from Y at a rate of 1/6 miles per minute, or 3/6 = 1/2 miles in three minutes. We know how long it takes x to move 1/2 mile from Y and because the speed of Y is constant, the rate at which x moves away from y will be constant as well.
SUFFICIENT

(D)
Retired Moderator
Joined: 06 Jul 2014
Posts: 1221
Location: Ukraine
Concentration: Entrepreneurship, Technology
GMAT 1: 660 Q48 V33
GMAT 2: 740 Q50 V40
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

02 May 2015, 15:00
1
apolo wrote:
Bunuel wrote:
While on a straight road, Car X and Car Y are traveling at different constant rates. If Car X is now 1 mile ahead of Car Y, how many minutes from now will Car X be 2 miles ahead of Car Y ?

(1) Car X is traveling at 50 miles per hour and Car Y is traveling at 40 miles per hour --> since we have the rates of both cars and the distance between them we can calculate any other question regarding them. Sufficient.

(2) Three minutes ago Car X was 1/2 mile ahead of Car Y --> car X gains 1/2 mile in every 3 minutes (since now it's 1 mile ahead), hence it'll gain additional 1 mile in next 6 minutes. Sufficient.

Hey Guys,

Don't u think that there is a problem in this questions?! How do we know that the cars are moving in the same direction? If they are moving away from each other, then the answer will be completely different, since in (1) the relative speed will be 90 miles/hr, while the answer to (2) remains the same, i.e. 6 minutes.
Notice that the question does not mention that the two cars are travelling in the same direction.
What do you think?

Hello apolo

I think when we have words such as "Car A ahead of Car B" or "Car A behind of Car B" is a sign of that they are drive in the same direction.

And when cars driving in different directions there is usually wording such as: "Two cars start off at the same point on a straight highway facing opposite directions."
_________________
Senior Manager
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 427
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Re: While on a straight road, car X and car Y are traveling at  [#permalink]

### Show Tags

11 Nov 2012, 01:54
Bro Bunuel,

How to solve this to get the time in secs if we consider this as 2 independent PS questions?

Regards,
Sachin
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.

Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595

My GMAT Journey : http://gmatclub.com/forum/end-of-my-gmat-journey-149328.html#p1197992
Intern
Joined: 20 Sep 2012
Posts: 18
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

22 Oct 2013, 11:43
WholeLottaLove wrote:
While on a straight road, Car X and Car Y are traveling at different constant rates. If Car X is now 1 mile ahead of Car Y, how many minutes from now will Car X be 2 miles ahead of Car Y ?

Car X is traveling at a greater speed/rate than Y.

(1) Car X is traveling at 50 miles per hour and Car Y is traveling at 40 miles per hour.

Car X is traveling at 5/6 miles/minute.
Car Y is traveling at 4/6 miles/minute.

Every minute, Car X moves away from car Y at a rate of (5/6) - (4/6) = 1/6 miles. Therefore, car X will have moved an additional mile away from car Y in six minutes.
SUFFICIENT

(2) Three minutes ago Car X was 1/2 mile ahead of Car Y.
In three minutes, car X managed to move 1/2 mile further away from Y. Because both cars were moving at constant rates, car x would have moved away from Y at a rate of 1/6 miles per minute, or 3/6 = 1/2 miles in three minutes. We know how long it takes x to move 1/2 mile from Y and because the speed of Y is constant, the rate at which x moves away from y will be constant as well.
SUFFICIENT

(D)

Correction in the explanation.
Every minute, Car X moves away from car Y at a rate of (5/6) - (4/6) = 1/3 miles. Therefore, car X will have to travel for 6 mins to move 2 miles farther away from car Y..
Manager
Joined: 18 May 2014
Posts: 56
Location: United States
Concentration: General Management, Other
GMAT Date: 07-31-2014
GPA: 3.99
WE: Analyst (Consulting)
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

18 May 2014, 10:56
Statement 1: Car X is traveling at 50 miles per hour and car Y is traveling at 40 miles per hour.
Notice that we could easily duplicate this scenario in real life.
Have Car X drive at 50 mph and car Y at 40mph.
Use a stopwatch to time how long it takes for Car X to be 2 miles ahead of Y.
As you can see, we have enough information to answer the target question
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: 3 minutes ago car X was 1/2 mile ahead of car Y.
If car X is presently 1 mile ahead, we can see that car X gains 1/2 mile every 3 minutes.
At that rate, car X will gain another 1 mile in 6 minutes.
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Hence D
Manager
Joined: 25 Jan 2015
Posts: 88
Location: United States
GMAT 1: 730 Q49 V41
While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

02 May 2015, 12:55
Bunuel wrote:
While on a straight road, Car X and Car Y are traveling at different constant rates. If Car X is now 1 mile ahead of Car Y, how many minutes from now will Car X be 2 miles ahead of Car Y ?

(1) Car X is traveling at 50 miles per hour and Car Y is traveling at 40 miles per hour --> since we have the rates of both cars and the distance between them we can calculate any other question regarding them. Sufficient.

(2) Three minutes ago Car X was 1/2 mile ahead of Car Y --> car X gains 1/2 mile in every 3 minutes (since now it's 1 mile ahead), hence it'll gain additional 1 mile in next 6 minutes. Sufficient.

Hey Guys,

Don't u think that there is a problem in this questions?! How do we know that the cars are moving in the same direction? If they are moving away from each other, then the answer will be completely different, since in (1) the relative speed will be 90 miles/hr, while the answer to (2) remains the same, i.e. 6 minutes.
Notice that the question does not mention that the two cars are travelling in the same direction.
What do you think?
Manager
Joined: 15 Mar 2015
Posts: 109
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

03 May 2015, 09:17
(1) Tells us that car X's relative speed to Y is 10 mph. With this we can easily find the time for X to increase the distance between the two cars with 1 mile. (1mile/10mph*60 minutes/hour=6 minutes)

(2) Tells us that increasing the distance 1/2 mile took 3 minutes. As the speeds in which X and Y are traveling are constant, we can conclude that X will increase the distance with an entire mile in double the time, 6 minutes.
_________________
I love being wrong. An incorrect answer offers an extraordinary opportunity to improve.
Intern
Joined: 20 Nov 2015
Posts: 1
Schools: Sloan '19, Duke '19
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

21 Mar 2016, 17:45
I didn´t get why 1 is sufficient. We don´t know the directions that the cars are going. If they are at the same direction the differece rate would be 10 mph, but if they are on opposite directions, it would be 90 mph. Could anyone help me?
Manager
Joined: 09 Aug 2016
Posts: 62
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

23 Sep 2016, 13:15
Why this is not E ?

The question doesn't mention anything about the direction of the cars.
Director
Status: Come! Fall in Love with Learning!
Joined: 05 Jan 2017
Posts: 537
Location: India
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

23 Feb 2017, 05:52
Prompt analysis
Car X and car Y are travelling in the same direction.

Superset
The time could be any positive real number.

Translation
In order to find the time, we need:
1# exact value of time
2# The speed of car X and car Y
3# any relation that would help to figure the speed or time.

Statement analysis
We will use the concept of relative speed.

St 1: relative speed of car X with respect to car Y is 50-40 = 10 mph. From this reference the car X has to travel 1 mile.therefore the time taken is 1/10 hrs or 6 minutes. ANSWER

St 2: in 3 minutes, car X has travelled ½ miles, therefreo car x will travel 1 mile in 6 minutes. ANSWER

Option D
_________________
GMAT Mentors
Intern
Joined: 24 Jun 2018
Posts: 31
Re: While on a straight road, Car X and Car Y are traveling at  [#permalink]

### Show Tags

04 Oct 2018, 05:15
Bunuel wrote:
While on a straight road, Car X and Car Y are traveling at different constant rates. If Car X is now 1 mile ahead of Car Y, how many minutes from now will Car X be 2 miles ahead of Car Y ?

(1) Car X is traveling at 50 miles per hour and Car Y is traveling at 40 miles per hour --> since we have the rates of both cars and the distance between them we can calculate any other question regarding them. Sufficient.

(2) Three minutes ago Car X was 1/2 mile ahead of Car Y --> car X gains 1/2 mile in every 3 minutes (since now it's 1 mile ahead), hence it'll gain additional 1 mile in next 6 minutes. Sufficient.

It might seem a bit silly but nowhere in the question, it was mentioned that the two cars are traveling in the opposite direction or same direction. Which according to me is relevant in deciding the answer? Bunuel, kindly let me know if I am correct or wrong?
_________________
A sentence which can make a happy person sad and a sad person happy- 'this TIME will change'
Re: While on a straight road, Car X and Car Y are traveling at   [#permalink] 04 Oct 2018, 05:15
Display posts from previous: Sort by