GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 29 May 2020, 08:35

### 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

# The XYZ river flows at 12 km/hr. A boy who can row at 2518 m/s

Author Message
TAGS:

### Hide Tags

Manager
Joined: 16 Apr 2019
Posts: 122
Location: India
Concentration: Marketing, Sustainability
GPA: 4
WE: Information Technology (Computer Software)
The XYZ river flows at 12 km/hr. A boy who can row at 2518 m/s  [#permalink]

### Show Tags

04 Oct 2019, 08:52
1
8
00:00

Difficulty:

55% (hard)

Question Stats:

58% (02:14) correct 43% (02:34) wrong based on 40 sessions

### HideShow timer Statistics

The XYZ river flows at 12 km/hr. A boy who can row at 25/18 m/s in still water had to cross it in the least possible time. The distance covered by the boy is how many times the width of the river XYZ?

A. 2.1
B. 2.3
C. 2.6
D. 2.9
E. 3.0
Manager
Joined: 20 Jul 2019
Posts: 63
Re: The XYZ river flows at 12 km/hr. A boy who can row at 2518 m/s  [#permalink]

### Show Tags

04 Oct 2019, 09:13
blowice27 wrote:
The XYZ river flows at 12 km/hr. A boy who can row at 25/18 m/s in still water had to cross it in the least possible time. The distance covered by the boy is how many times the width of the river XYZ?

A. 2.1
B. 2.3
C. 2.6
D. 2.9
E. 3.0

Speed of the river XYZ = 12 kmph

Speed of the boy = 5 kmph

Let the time taken by the boy to cross the river in still water = T

Width of the river = 5T
The boy takes the least time when he is travelling directly across the river.

But the river current pushes him in a direction perpendicular to the flow,
Distance travelling along the river = 12T

Effective distance travelled by boy = √(12T)2+(5T)2=13T

Distance covered by the boy
width of the river
=
13T
5T
= 2.6

Posted from my mobile device
Intern
Joined: 01 Jul 2019
Posts: 34
Re: The XYZ river flows at 12 km/hr. A boy who can row at 2518 m/s  [#permalink]

### Show Tags

05 Apr 2020, 07:56
Quote:
.Effective distance travelled by boy = √(12T)2+(5T)2=13T

Distance covered by the boy
width of the river
=
13T
5T
= 2.6

Posted from my mobile device

I'm not following this part can you please rewrite this out??? TY
Intern
Joined: 27 Oct 2019
Posts: 6
Re: The XYZ river flows at 12 km/hr. A boy who can row at 2518 m/s  [#permalink]

### Show Tags

05 Apr 2020, 08:44
Width of the river is the ideal route to row but river flows -> it will make the route becomes hypotenuse of perpendicular triangle

Hope it helps

Posted from my mobile device
Intern
Joined: 01 Jul 2019
Posts: 34
Re: The XYZ river flows at 12 km/hr. A boy who can row at 2518 m/s  [#permalink]

### Show Tags

05 Apr 2020, 08:48
TY Could you please rewrite the last part of equation so I can see how you solved it?im missing with the A^2+B^2=c^2 solution

Posted from my mobile device
Re: The XYZ river flows at 12 km/hr. A boy who can row at 2518 m/s   [#permalink] 05 Apr 2020, 08:48