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

 It is currently 12 Dec 2019, 20:11

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

A car going at 40 miles per hour set out on an 80-mile trip at 9:00

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 59712
A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

01 Dec 2015, 04:27
10
00:00

Difficulty:

45% (medium)

Question Stats:

74% (02:40) correct 26% (02:43) wrong based on 344 sessions

HideShow timer Statistics

A car going at 40 miles per hour set out on an 80-mile trip at 9:00 A.M. Exactly 10 minutes later, a second car left from the same place and followed the same route. How fast, in miles per hour, was the second car going if it caught up with the first car at 10:30 A.M.?

(A) 45

(B) 50

(C) 53

(D) 55

(E) 60

_________________
Verbal Forum Moderator
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 2435
Location: India
Concentration: General Management, Strategy
Schools: Kelley '20, ISB '19
GPA: 3.2
WE: Information Technology (Consulting)
Re: A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

01 Dec 2015, 05:54
5
6
Let Car A = car that starts at 9 AM
Car B = car that starts at 9:10 AM
Time for which car A travels at speed of 40 m per hour = 1.5 hours
Distance travelled by Car A = 40 *1.5 = 60 miles

Since Car B catches up Car A at 10:30 , time = 80 mins = 4/3 hour
Speed of Car B = 60/(4/3) = 45 miles per hour

_________________
When everything seems to be going against you, remember that the airplane takes off against the wind, not with it. - Henry Ford
The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long
General Discussion
Board of Directors
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4834
Location: India
GPA: 3.5
Re: A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

01 Dec 2015, 12:04
1
1
Bunuel wrote:
A car going at 40 miles per hour set out on an 80-mile trip at 9:00 A.M. ....... if it caught up with the first car at 10:30 A.M.?
Distance covered by the car in 1.5 hours ( 10:30 A.M. - 9:00 A.M.) is 1.5 * 40 = 60 miles
Bunuel wrote:
a second car left from the same place and followed the same route. How fast, in miles per hour, was the second car going if it caught up with the first car at 10:30 A.M.?
Now car A has covered 60 miles by 10:30 A.M , so car B must also cover the same distance in ( 10:30 A.M - 9:10 A.M.) 80/60 hr

So, speed of car B must be = 60 * 6/8 i.e. 45 miles per hour

_________________
Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )
Retired Moderator
Joined: 22 Jun 2014
Posts: 1090
Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
Re: A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

02 Dec 2015, 04:17
1
Distnace covered in 1.5 hr (90 minutes i.e. between 09:00AM - 10:30AM ) = 60 miles (40 * 1.5)

Second covered 60 miles in 80 minutes (i.e. 10 minutes less than the first car because second car started at 09:10AM).

Speed of the second car = 60miles / (80/60) hour = 45miles/hour

Option A is correct.
_________________
CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2977
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

02 Dec 2015, 08:29
Bunuel wrote:
A car going at 40 miles per hour set out on an 80-mile trip at 9:00 A.M. Exactly 10 minutes later, a second car left from the same place and followed the same route. How fast, in miles per hour, was the second car going if it caught up with the first car at 10:30 A.M.?

(A) 45

(B) 50

(C) 53

(D) 55

(E) 60

Distance travelled by first car in 10 mins = 40/6 = 20/3 miles

Relative Distance between two cars at the time second car starts = 20/3 miles

Relative speed of two cars = (s-14) where s is the speed of second car

Time taken by second car to catch first car = (9:10 to 10:30) = 1 hour 20 mins = 4/3 hours

Relative speed = Relative Distance / time

(s-40) = (20/3)/(4/3) = 5
i.e. s = 5+40 = 45 miles per hour

_________________
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
Joined: 17 Aug 2015
Posts: 97
Re: A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

07 May 2016, 10:02
1
Here is one other way to solve the problem.
Car 1 took 90 minutes to cover some distance, whereas the second car took 80 minutes to do the same. We can set up following equation-
Ratio of time = inverse of the ratio of speed
80/90 = 40/x => 2/90=1/x=> x = 45m.

the problem can also be solved by the relative speed equation
distance to be caught up by the second car is equal to the distance that the first car did in first 10 minutes
40/60*10
This is to be caught up in 80 minutes or 8/6 hours
40/60*10/(x-40) = 8/6. Solve this to get x = 45.
Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8692
Location: United States (CA)
A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

01 Jun 2017, 10:10
1
Bunuel wrote:
A car going at 40 miles per hour set out on an 80-mile trip at 9:00 A.M. Exactly 10 minutes later, a second car left from the same place and followed the same route. How fast, in miles per hour, was the second car going if it caught up with the first car at 10:30 A.M.?

(A) 45

(B) 50

(C) 53

(D) 55

(E) 60

We are given that a car left at 9 a.m. traveling at a rate of 40 mph and another car left 10 minutes later. Since the second car caught up to the first car at 10:30 a.m., the time of the first car is 1.5 hours and the distance is 1.5 x 40 = 60 miles.

If we let r = the rate of the second car, the distance of the second car is:

r x (1 hour 20 minutes)

r x (1 1/3 hours)

r x (4/3) = 4r/3

Since the second car catches up to the first car we can set the distances equal and determine r:

4r/3 = 60

4r = 180

r = 45

_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Manager
Joined: 22 Nov 2016
Posts: 205
Location: United States (CA)
Schools: Haas EWMBA '22
GMAT 1: 640 Q43 V35
GPA: 3.4
A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

25 Jun 2017, 16:29
Very little calculation here.
The second car travelled for 80 minutes and covered 60 miles. The question asks the speed of the second car in miles per hour. OR
How many miles did the second car travel in 60mins?

80mins------60miles
60mins------?
$$\frac{(60*60)}{80}$$ = $$\frac{(3600)}{80}$$ = slightly over 40 but less than 50

Manager
Joined: 02 Jan 2017
Posts: 58
Location: India
Schools: Oxford "21
Re: A car going at 40 miles per hour set out on an 80-mile trip at 9:00  [#permalink]

Show Tags

17 May 2019, 18:47
Bunuel wrote:
A car going at 40 miles per hour set out on an 80-mile trip at 9:00 A.M. Exactly 10 minutes later, a second car left from the same place and followed the same route. How fast, in miles per hour, was the second car going if it caught up with the first car at 10:30 A.M.?

(A) 45

(B) 50

(C) 53

(D) 55

(E) 60

Hi GMATPrepNow

COuld you please help me with this solution . I got the realtive distance of the gap as 20/3 miles. I am not sure how to proceed next
Re: A car going at 40 miles per hour set out on an 80-mile trip at 9:00   [#permalink] 17 May 2019, 18:47
Display posts from previous: Sort by