Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

 It is currently 17 Jul 2019, 01:38

### 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 certain car increased its avarage speed by 5 miles per

Author Message
TAGS:

### Hide Tags

Manager
Joined: 01 Dec 2011
Posts: 63
A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

08 Feb 2012, 09:11
4
1
26
00:00

Difficulty:

25% (medium)

Question Stats:

75% (01:57) correct 25% (02:18) wrong based on 604 sessions

### HideShow timer Statistics

A certain car increased its average speed by 5 miles per hour in each successive 5-minute interval after the first interval. If in the first 5-minute interval its average speed was 20 miles per hour, how many miles did the car travel in the third 5-minute interval?

A) 1.0
B) 1.5
C) 2.0
D) 2.5
E) 3.0

_________________
http://en.wikipedia.org/wiki/Kudos
Math Expert
Joined: 02 Sep 2009
Posts: 56266
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

08 Feb 2012, 09:24
6
5
fiendex wrote:
A certain car increased its average speed by 5 miles per hour in each successive 5-minute interval after the first interval. If in the first 5-minute interval its average speed was 20 miles per hour, how many miles did the car travel in the third 5-minute interval?

A) 1.0
B) 1.5
C) 2.0
D) 2.5
E) 3.0

In the third time interval the average speed of the car was 20+5+5=30 miles per hour;
In 5 minutes (1/12 hour) at that speed car would travel 30*1/12=2.5 miles.

_________________
##### General Discussion
Intern
Joined: 06 Nov 2011
Posts: 35
Location: Germany
Concentration: Entrepreneurship, General Management
GMAT Date: 03-10-2012
GPA: 3
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

07 Mar 2012, 09:53
Damn it. Thanks Bunuel.
I calculated the total milage instead of only that of the third segment!!
Manager
Joined: 11 Sep 2013
Posts: 141
Concentration: Finance, Finance
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

21 Apr 2014, 02:01
1
1
Bunuel wrote:
fiendex wrote:
A certain car increased its average speed by 5 miles per hour in each successive 5-minute interval after the first interval. If in the first 5-minute interval its average speed was 20 miles per hour, how many miles did the car travel in the third 5-minute interval?

A) 1.0
B) 1.5
C) 2.0
D) 2.5
E) 3.0

In the third time interval the average speed of the car was 20+5+5=30 miles per hour;
In 5 minutes (1/12 hour) at that speed car would travel 30*1/12=2.5 miles.

Had the question asked, how long did the car travel up to third minute interval, how could we have found the answer. Please explain it.
Math Expert
Joined: 02 Sep 2009
Posts: 56266
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

21 Apr 2014, 02:11
1
1
Raihanuddin wrote:
Bunuel wrote:
fiendex wrote:
A certain car increased its average speed by 5 miles per hour in each successive 5-minute interval after the first interval. If in the first 5-minute interval its average speed was 20 miles per hour, how many miles did the car travel in the third 5-minute interval?

A) 1.0
B) 1.5
C) 2.0
D) 2.5
E) 3.0

In the third time interval the average speed of the car was 20+5+5=30 miles per hour;
In 5 minutes (1/12 hour) at that speed car would travel 30*1/12=2.5 miles.

Had the question asked, how long did the car travel up to third minute interval, how could we have found the answer. Please explain it.

I guess you mean the total distance covered in three 5-minute intervals.

The distance covered in the first 5-minute interval = (time)(average speed) = 1/12*20;
The distance covered in the second 5-minute interval = (time)(average speed) = 1/12*25;
The distance covered in the third 5-minute interval = (time)(average speed) = 1/12*30.

Total distance = 1/12(20+25+30) = 75/12 miles.
_________________
SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1787
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

21 Apr 2014, 22:38
10

Attachments

car.jpg [ 15.09 KiB | Viewed 17060 times ]

_________________
Kindly press "+1 Kudos" to appreciate
EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 14563
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

27 Apr 2015, 18:21
Hi All,

Here's a similarly-themed question:

the-average-speed-of-a-car-decreased-by-3-miles-per-hour-12994.html#p1520197

GMAT assassins aren't born, they're made,
Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****

# Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save \$75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/
Intern
Joined: 28 Oct 2015
Posts: 22
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

20 Jan 2016, 08:34
1
Miles per minute on the third interval: 30/60 =1/2. After 5 minutes=( 1/2)*5= 2.5
Manager
Joined: 22 Feb 2015
Posts: 75
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

21 Jan 2016, 05:21
After first 5-minute interval, speed increases to 25 miles per hour
After second 5-minute interval, speed increases to 30 miles per hour
So, in the third 5-minute interval, speed is 30 miles per hour

60 minutes corresponds to 30 miles per hour
So, 5-minutes corresponds to (30/60)*5 = 2.5 miles
VP
Joined: 09 Mar 2016
Posts: 1273
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

18 Feb 2018, 10:39
Quote:
Had the question asked, how long did the car travel up to third minute interval, how could we have found the answer. Please explain it.

I guess you mean the total distance covered in three 5-minute intervals.

The distance covered in the first 5-minute interval = (time)(average speed) = 1/12*20;
The distance covered in the second 5-minute interval = (time)(average speed) = 1/12*25;
The distance covered in the third 5-minute interval = (time)(average speed) = 1/12*30.

Total distance = 1/12(20+25+30) = 75/12 miles.[/quote]

Bunuel how did you calculate time ? 1/12 ...does it means that it takes 5 minutes for every 12 miles ?
Math Expert
Joined: 02 Sep 2009
Posts: 56266
A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

18 Feb 2018, 10:41
1
dave13 wrote:

Bunuel how did you calculate time ? 1/12 ...does it means that it takes 5 minutes for every 12 miles ?

5 minutes is 1/12 hour.
_________________
VP
Joined: 09 Mar 2016
Posts: 1273
A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

19 Feb 2018, 08:54
Bunuel wrote:
dave13 wrote:

Bunuel how did you calculate time ? 1/12 ...does it means that it takes 5 minutes for every 12 miles ?

5 minutes is 1/12 hour.

hi Bunuel, if i change 5 minutes into 10 minutes interval.

so:
first interval the speed id 20 km per hour
second interval is 30 km per hour
third interval is 40 km per hour

Speed = $$\frac{40 km (distance)}{60 minutes (time)}$$

Time in 10-minute interval, means what distance did the car in 10 minute interval at a speed of 40 km per hour.

Time = $$\frac{distance}{speed}$$

Distance = $$speed * time$$ ---> $$\frac{40 km (distance)}{60 minutes (time)}$$ * 10 = 6,7 miles

Is my understanding correct ?

thank you
Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2823
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

21 Feb 2018, 14:12
fiendex wrote:
A certain car increased its average speed by 5 miles per hour in each successive 5-minute interval after the first interval. If in the first 5-minute interval its average speed was 20 miles per hour, how many miles did the car travel in the third 5-minute interval?

A) 1.0
B) 1.5
C) 2.0
D) 2.5
E) 3.0

The rate of the car in the first interval was 20 mph, in the second it was 25 mph, and in the third it was 30 mph.

Since 5 minutes = 5/60 = 1/12 hour, the distance traveled in the third interval was 30 x 1/12 = 30/12 = 5/2 = 2.5 miles.

_________________

# Jeffrey Miller

Jeff@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.

Status: booyeh!
Joined: 26 May 2017
Posts: 15
Location: India
Concentration: Strategy, Marketing
Re: A certain car increased its avarage speed by 5 miles per  [#permalink]

### Show Tags

17 May 2019, 20:08
speed = distance * time

speed on 3rd interval = 20+(5+5) = 30

time = speed/distance; (30/60)*5 = 2.5 minutes
Re: A certain car increased its avarage speed by 5 miles per   [#permalink] 17 May 2019, 20:08
Display posts from previous: Sort by