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

It is currently 16 Dec 2018, 15:16

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
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • FREE Quant Workshop by e-GMAT!

     December 16, 2018

     December 16, 2018

     07:00 AM PST

     09:00 AM PST

    Get personalized insights on how to achieve your Target Quant Score.
  • Free GMAT Prep Hour

     December 16, 2018

     December 16, 2018

     03:00 PM EST

     04:00 PM EST

    Strategies and techniques for approaching featured GMAT topics

Car X began traveling at an average speed of 35 miles per hour. After

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51229
Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 02 Sep 2015, 21:50
2
12
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

66% (02:41) correct 34% (03:07) wrong based on 353 sessions

HideShow timer Statistics

Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 49 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?

(A) 105
(B) 120
(C) 140
(D) 147
(E) 168

Kudos for a correct solution.

_________________

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

Most Helpful Community Reply
Manager
Manager
User avatar
Joined: 04 May 2015
Posts: 71
Concentration: Strategy, Operations
WE: Operations (Military & Defense)
Premium Member
Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 03 Sep 2015, 15:53
4
1
Bunuel wrote:
Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 49 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?

(A) 105
(B) 120
(C) 140
(D) 147
(E) 168

Kudos for a correct solution.


These type of questions are still my biggest weakness, but I think explaining it help me... Feel free to give me feedback on my method. Please also bear with the fact that I am explaining every single step in my reasoning... Maybe it will help someone one day.

Rate * Distance = Time
Where \(T =\) time Car Y driving in Hours & \(D =\) Distance in Miles

Car X: \(35 * (T + \frac{6}{5}) = D\)
Car Y: \(49 * T = D\)

---> \(35(T + \frac{6}{5}) = 49T\)
---> \(35T + \frac{210}{5} = 49T\)
---> \(35T + 42 = 49T\)
---> \(14T = 42\)
---> \(T = \frac{42}{14} = 3\)

So we know that They both drove the same distance after Car Y had been driving for 3 hours. The question asks how far Car X had driven after this amount of time ---> \(35 * 3 = 105\) miles

Answer = A
_________________

If you found my post useful, please consider throwing me a Kudos... Every bit helps :)

General Discussion
Intern
Intern
User avatar
Joined: 09 May 2012
Posts: 18
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 03 Sep 2015, 01:17
2
1
Car X would have traveled 42 miles in 72 minutes or by the time Car Y started.
Now, Car Y has to cover 42 extra miles while running alongwith Car X.
Since Car Y covers (49 - 34 = 14) 14 additional miles each hour, it would take 3 hours to cover the same distance as Car X.
Hence, Car X would have traveled for 3 hours, thereby covering (35 X 3 = 105 miles) from the time car Y began travelling.

Therefore, A is the answer.
Manager
Manager
avatar
Joined: 29 Jul 2015
Posts: 158
GMAT ToolKit User
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 03 Sep 2015, 08:13
2
Bunuel wrote:
Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 49 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?

(A) 105
(B) 120
(C) 140
(D) 147
(E) 168

Kudos for a correct solution.



Car Y began travelling after 72 minutes or 1.2 hours.
Let t be the time for which car Y travelled before it stopped.
Both cars stop when they have travelled the same distance.
So,
35(t+1.2) = 49t
or 5t+6=7t
or t=3

Distance travelled by car X from the time car Y began traveling until both cars stopped is

35 x 3
= 105 miles

Answer:- A
Manager
Manager
avatar
Joined: 10 Aug 2015
Posts: 103
GMAT ToolKit User
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 03 Sep 2015, 10:35
1
1
Solution:

Let t be time traveled by x. So we have to subtract distance traveled in 72 min to get the answer.
So, ans = 35(t -1.2)
But, total distances traveled is same.
So,49(t-1.2) = 35t ---> 14t =49(1.2) -->t= 7(0.6)=4.2.
ans = 35(4.2-1.2) = 105

Option A
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51229
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 06 Sep 2015, 05:15
Bunuel wrote:
Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 49 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?

(A) 105
(B) 120
(C) 140
(D) 147
(E) 168

Kudos for a correct solution.


KAPLAN OFFICIAL SOLUTION:

Step 1 is to determine how far car X traveled during the 72 minutes before car Y has started. To do this, we first convert 72 minutes to 6/5 of an hour (that’s 72/60 simplified), in order to make sure our units match, as our speed is given in miles per hour. Since rate * time = distance, we know that car X traveled 35mph * 6/5 hours = 42 miles.

Step 2 we need to determine a relative rate. We do this in order to figure out how many miles car Y gains on car X each hour. To calculate this, subtract the rate of car X from the rate of car Y. 49mph – 35mph = 14mph, which is our relative rate in miles per hour, or the rate that Y gains on X per hour.

Step 3 take the distance car Y must gain on car X (that’s 42 miles, from step 1) and divide it by the number of miles car Y gains on X in an hour (that’s 14 mph from step 2) in order to find the number of hours it will take for both cars to travel the same distance: 42mi/14mph = 3 hours.

Finally, we are asked to find how far car X traveled after car Y starts. We use the time we calculated from step 3, which is 3 hours, and multiply it by car X’s rate (35mph). This gives us 3hrs * 35mph = 105 miles, which is choice (A) and the correct answer to this problem.
_________________

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

Director
Director
User avatar
G
Joined: 23 Jan 2013
Posts: 568
Schools: Cambridge'16
Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 19 Oct 2015, 00:26
35*(6/5 + x) = 49x

42+35x=49x

x=3, so 35*3=105

A
CEO
CEO
User avatar
P
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2711
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 19 Oct 2015, 04:20
1
Bunuel wrote:
Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 49 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?

(A) 105
(B) 120
(C) 140
(D) 147
(E) 168

Kudos for a correct solution.


Car X travels for 72 minutes before car Y starts so the distance travelled by car X in 72 mins (i.e. 6/5 Hours) = Lead of car X over car Y = 35*(6/5) = 42 Miles

Relative Speed of Y with respect to speed of X = 49-35 = 14 miles/hour

Time taken by Y to cover the Relative Distance between X and Y in order to travel as much distance as X does = Relative Distance / Relative Speed = 42/14 = 3 hours

Distance travelled by Y in 3 hours = 49*3 = 147 miles

SO the Distance to be calculated (Travelled by X after Y started) = 147-42 = 105 miles

Answer: option A
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Manager
Manager
avatar
B
Joined: 17 Aug 2015
Posts: 100
GMAT ToolKit User
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 13 Aug 2016, 10:20
This is a catch up question but does not easily tell us that. It says that when they both stopped they had covered the same distance from the starting point. Both cars travelling the same distance after X having left early means Y caught up. So we can apply the relative speed formula.

In my first attempt I didnt get that very clearly, so conservatively I applied another method which is below:
Car X travelled the same distance as Y when it stopped. This means
35*(t+72/60) = 49*t. This gives t = 3.
Now the question does not ask the total distance. It only wants to know how many miles did X travel after Y left. This is t*35 = 3*35 = 105.

For those that understood straight that this is a catch up problem , I will say great job decoding that! But the other method is a good one when in doubt.
Intern
Intern
avatar
Joined: 21 Jun 2016
Posts: 5
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 22 Aug 2016, 01:06
Bunuel wrote:
Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 49 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?

(A) 105
(B) 120
(C) 140
(D) 147
(E) 168

Kudos for a correct solution.


By the time Car Y started to travel Car X has already traveled 42 miles. (35*6/5)
And we know that time is constant after Y started to travel : let it be T
so 35T + 42 = 49T
T = 3
So we know that Car X and Y traveled 3 hours until they have stopped.
35*3 = 105
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9184
Premium Member
Re: Car X began traveling at an average speed of 35 miles per hour. After  [#permalink]

Show Tags

New post 22 Sep 2017, 09:53
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: Car X began traveling at an average speed of 35 miles per hour. After &nbs [#permalink] 22 Sep 2017, 09:53
Display posts from previous: Sort by

Car X began traveling at an average speed of 35 miles per hour. After

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


Copyright

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®.