Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 26 May 2016, 18:03

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A boat travels for three hours with a current of 3 mph and

Author Message
TAGS:

Hide Tags

SVP
Joined: 16 Oct 2003
Posts: 1811
Followers: 4

Kudos [?]: 96 [0], given: 0

A boat travels for three hours with a current of 3 mph and [#permalink]

Show Tags

24 Jul 2004, 22:33
00:00

Difficulty:

(N/A)

Question Stats:

60% (02:21) correct 40% (00:04) wrong based on 21 sessions

HideShow timer Statistics

A boat travels for three hours with a current of 3 mph and then returns the same distance against the current in four hours. What is the boat's speed in calm water? How far did the boat travel one way?
Director
Joined: 05 May 2004
Posts: 577
Location: San Jose, CA
Followers: 2

Kudos [?]: 50 [0], given: 0

Re: PS-Boat Upstream and Downstream [#permalink]

Show Tags

24 Jul 2004, 22:50
Bhai wrote:
A boat travels for three hours with a current of 3 mph and then returns the same distance against the current in four hours. What is the boat's speed in calm water? How far did the boat travel one way?

Let velocity of boat in calm water be V
(V+3)*3 = (V-3)*4 ... same distance
Solving V= 21
Joined: 31 Dec 1969
Location: India
Concentration: Marketing, General Management
GMAT 1: 710 Q49 V0
GMAT 2: 700 Q V
GMAT 3: 740 Q40 V50
GMAT 4: 700 Q48 V38
GMAT 5: 710 Q45 V41
GMAT 6: 680 Q47 V36
GMAT 7: Q42 V44
GMAT 8: Q42 V44
GMAT 9: 740 Q49 V42
GMAT 10: 740 Q V
GMAT 11: 500 Q47 V33
GPA: 3.3
WE: Sales (Investment Banking)
Followers: 0

Kudos [?]: 146 [0], given: 97169

Show Tags

24 Jul 2004, 23:09
The distance travelled will always be fixed.

So distance = 3mph * 3h = 9miles

Speed will be (s+3)*3 = (s-3)*4 assuming the current does not change direction and stays constant

so S = 21mph
GMAT Club Legend
Joined: 07 Jul 2004
Posts: 5062
Location: Singapore
Followers: 28

Kudos [?]: 267 [0], given: 0

Show Tags

24 Jul 2004, 23:10
Director
Joined: 16 Jun 2004
Posts: 893
Followers: 2

Kudos [?]: 41 [0], given: 0

Show Tags

25 Jul 2004, 05:28
Let B be the velocity of the boat and U be the velocity of the stream.

(B+U) x 3 = (B-U) x 4

(3+B) x 3 = (B-3)x 4

9+3B=4B-12

B=21

The boat travelled (21-3) x 4hrs = 72 miles one way.
GMAT Club Legend
Joined: 07 Jul 2004
Posts: 5062
Location: Singapore
Followers: 28

Kudos [?]: 267 [0], given: 0

Show Tags

25 Jul 2004, 07:59
Venksune, you got the distance right... I overlooked the question when I calculated the distance travelled...
CIO
Joined: 09 Mar 2003
Posts: 463
Followers: 2

Kudos [?]: 40 [0], given: 0

Show Tags

25 Jul 2004, 08:35
same answers and methods as everyone else:

3(r+3)=4(r-3)
r=21
D=72
Senior Manager
Joined: 26 Jan 2004
Posts: 402
Location: India
Followers: 1

Kudos [?]: 0 [0], given: 0

Show Tags

26 Jul 2004, 06:46
Ans,
21mph speed.
72miles distance.

(Approach, same as adopted by others)
Manager
Joined: 12 Dec 2012
Posts: 230
GMAT 1: 540 Q36 V28
GMAT 2: 550 Q39 V27
GMAT 3: 620 Q42 V33
GPA: 2.82
WE: Human Resources (Health Care)
Followers: 4

Kudos [?]: 68 [0], given: 181

Re: A boat travels for three hours with a current of 3 mph and [#permalink]

Show Tags

08 Apr 2013, 12:58
_________________

My RC Recipe
http://gmatclub.com/forum/the-rc-recipe-149577.html

My Problem Takeaway Template
http://gmatclub.com/forum/the-simplest-problem-takeaway-template-150646.html

MBA Section Director
Affiliations: GMAT Club
Joined: 22 Feb 2012
Posts: 2559
Location: India
City: Pune
GPA: 3.4
Followers: 309

Kudos [?]: 2234 [1] , given: 1773

Re: A boat travels for three hours with a current of 3 mph and [#permalink]

Show Tags

08 Apr 2013, 13:22
1
KUDOS
Expert's post
TheNona wrote:

Let the speed in still water be x
Speed of stream = 3

So
Speed while going downstream = x+3
Time while going downstream = 3
Speed while going upstream = x-3
Time while going upstream = 4

Since distance traveled through both ways is same and time ratio being $$\frac{3}{4}$$, the speed ratio must be $$\frac{4}{3}$$

$$\frac{Speed downstream}{Speed upstream}$$ = $$\frac{4}{3}$$

$$\frac{x+3}{x-3}$$ = $$\frac{4}{3}$$ ------> 3x + 9 = 4x - 12 ----------> x=21

Speed in still water = 21

Distance = Speed X Time
Distance = (x+3)3 = 24 X 3 = 72
or
Distance = (x-3)4 = 18 X 4 = 72

Regards,

Narenn
_________________
Re: A boat travels for three hours with a current of 3 mph and   [#permalink] 08 Apr 2013, 13:22
Similar topics Replies Last post
Similar
Topics:
Steve traveled the first 2 hours of his journey at 40 mph and the last 1 14 Mar 2016, 07:26
Jim travels the first 3 hours of his journey at 60 mph speed and the 3 14 Mar 2016, 07:21
2 The current in a river is 4 mph. A boat can travel 20 mph in still wat 2 24 Jan 2016, 06:38
1 Boat travelling upstream 4 16 Mar 2011, 01:11
Steve traveled the first 2 hours of his journey at 40 mph an 4 22 Oct 2010, 05:51
Display posts from previous: Sort by