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

 It is currently 19 Jul 2018, 06:54

### 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 plane takes off from New York and travels a total distance of 1440KM

Author Message
TAGS:

### Hide Tags

Manager
Status: Math Tutor
Joined: 12 Aug 2017
Posts: 74
GMAT 1: 750 Q50 V42
WE: Education (Education)
A plane takes off from New York and travels a total distance of 1440KM [#permalink]

### Show Tags

19 Aug 2017, 11:03
1
00:00

Difficulty:

45% (medium)

Question Stats:

70% (02:08) correct 30% (02:40) wrong based on 82 sessions

### HideShow timer Statistics

A plane takes off from New York and travels a total distance of 1440 KMs to its destination at an average speed of 80 m/s. It then returns along the same route at twice its original speed. How much time does the trip takes? (Note 1000 m = 1 KM)

A. 0 hours 30 minutes
B. 2 hours 20 minutes
C. 5 hours
D. 7 hours 30 minutes
E. 10 hours

_________________

Abhishek Parikh
Math Tutor
Whatsapp- +919983944321
Mobile- +971568653827
Website: http://www.holamaven.com

Manager
Status: Math Tutor
Joined: 12 Aug 2017
Posts: 74
GMAT 1: 750 Q50 V42
WE: Education (Education)
Re: A plane takes off from New York and travels a total distance of 1440KM [#permalink]

### Show Tags

19 Aug 2017, 11:08
While moving from New York to its destination,
Distance = 1440
Speed = 80m/s = 80*$$\frac{18}{5}$$ km/h = 16*18 km/h
Time = $$\frac{1440}{16*18}$$ = 5 hrs.
While return speed gets doubled so time will get halved. i.e. 2.5 hours
Total time = 5+2.5 = 7.5 hours. Option D
_________________

Abhishek Parikh
Math Tutor
Whatsapp- +919983944321
Mobile- +971568653827
Website: http://www.holamaven.com

BSchool Forum Moderator
Joined: 26 Feb 2016
Posts: 2946
Location: India
GPA: 3.12
A plane takes off from New York and travels a total distance of 1440KM [#permalink]

### Show Tags

19 Aug 2017, 11:18
Formula used :Time = $$\frac{Distance}{Speed}$$

Given data:
$$Distance = 1440km$$ | $$Speed = 80 m/s$$

In order to convert a speed from m/s to km/hr, we must multiply it by a factor of $$\frac{18}{5}$$

Speed in km/hour : $$80*\frac{18}{5} = 288$$ km/hr

Therefore, the speed on the other side is $$2*288 = 576$$ km/hr

Time taken to cover the distance : $$\frac{1440}{288} + \frac{1440}{576} = 5 + \frac{5}{2}$$ = 7 hours and 30 minutes(Option D)
_________________

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

Intern
Joined: 11 Jul 2017
Posts: 3
Re: A plane takes off from New York and travels a total distance of 1440KM [#permalink]

### Show Tags

19 Aug 2017, 19:43
I think this method saves time:

Step 1: Transform 80 meter per second into kilometers per hour.

-The plane travels 80 meters in 1 second, so it travels 4800 meters in one minute (80 meters x 60 seconds).
-4800 meters per minute are 4.8 kilometers per minute.
-The plane travels 4.8 kilometers per minute, so it travels 288 kilometers per hour (4.8 kilometers x 60 minutes).

Step 2: The time it takes the plane to travel is the distance (1440) divided by the rate (288km per hour). NEVER divide such kind of numbers, approximations are time-saving. 1440km are close to 1500, and 288km per hour is close to 300km per hour. 1500km divided by 300km per hour is 5 hours.

Step 3: The time it took the plane to travel 1440 was approx. 5 hours. But the second time the plane flew at double the rate. Therefore, the second trip took 2.5 hours. 5 + 2.5 is 7.5. The answer is D.
Re: A plane takes off from New York and travels a total distance of 1440KM   [#permalink] 19 Aug 2017, 19:43
Display posts from previous: Sort by

# Events & Promotions

 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®.