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

 It is currently 22 Jan 2019, 15:55

### 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

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### The winners of the GMAT game show

January 22, 2019

January 22, 2019

10:00 PM PST

11:00 PM PST

In case you didn’t notice, we recently held the 1st ever GMAT game show and it was awesome! See who won a full GMAT course, and register to the next one.
• ### Key Strategies to Master GMAT SC

January 26, 2019

January 26, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.

# Tom drives to take a GMAT test at an average speed of 50 kilometers pe

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

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52390
Tom drives to take a GMAT test at an average speed of 50 kilometers pe  [#permalink]

### Show Tags

07 Oct 2016, 01:40
00:00

Difficulty:

15% (low)

Question Stats:

82% (02:10) correct 18% (02:13) wrong based on 114 sessions

### HideShow timer Statistics

Tom drives to take a GMAT test at an average speed of 50 kilometers per hour. The moment he arrives at his destination, he realizes that he was confused and that the test would take place on the next day. He immediately returns home the same way, at an average speed of 30 kilometers per hour. If Tom drove 40 kilometers from home to the GMAT test location, how many kilometers per hour is Tom's average speed during his entire journey?

A. 35
B. 37.5
C. 40
D. 42.5
E. 45

_________________
Senior PS Moderator
Joined: 26 Feb 2016
Posts: 3334
Location: India
GPA: 3.12
Re: Tom drives to take a GMAT test at an average speed of 50 kilometers pe  [#permalink]

### Show Tags

07 Oct 2016, 04:00
Since the distance for the travel is the same,
the formula for average speed = (2*a*b)/(a+b)

Substituting values a=50,b=30 in the equation,
we get average speed 37.5kmph(Option B)
_________________

You've got what it takes, but it will take everything you've got

Manager
Joined: 08 Sep 2015
Posts: 63
Re: Tom drives to take a GMAT test at an average speed of 50 kilometers pe  [#permalink]

### Show Tags

07 Oct 2016, 18:44
Avg. speed = (Distance to GMAT + Distance from GMAT) /( Time to GMAT + Time from GMAT)
Since Tom came back the same way => total distance traveled is 40 x 2 = 80 km

Time to GMAT = 40 / 50 = 4/5
Time from GMAT = 40 / 30 = 4/3

Total time: 4/5 +4/3 = 32/15
Avg. speed = 80 /(32/15) = 75/2 = 37.5 -> option B
Director
Joined: 24 Nov 2015
Posts: 514
Location: United States (LA)
Re: Tom drives to take a GMAT test at an average speed of 50 kilometers pe  [#permalink]

### Show Tags

19 Feb 2017, 23:11
Distance between Tom's home to the GMAT test location is not relevant in calculating the average speed of his journey
formula for average speed = $$\frac{2a*b}{a+b}$$

where a is speed of tom when he goes from his home to gmat test location
and b is speed when tom comes back from gmat test location to his home
average speed =$$\frac{2*50*30}{50+30}$$ = 37.5

correct answer - B
Re: Tom drives to take a GMAT test at an average speed of 50 kilometers pe &nbs [#permalink] 19 Feb 2017, 23:11
Display posts from previous: Sort by

# Tom drives to take a GMAT test at an average speed of 50 kilometers pe

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

 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®.