tass@ wrote:Two boats on the opposite shores of a river start moving towards each other, When they pass each other they are 750 yards from one shoreline. They each continue to the opposite shore, immediately turn around and start back. When they meet again they are 250 yards from the other shoreline. Each boat maintains a constant speed throughout. How wide is the river?
a)2000 b)1800 c) 1000 d) 1200
Let M and N be the two boats.
First meeting:
M-----><-----N
To meet the first time, M and N work together to travel with width of the river ONCE.
Second meeting:
<-----N M----->
------> <------
To meet the second time, M and N work together to travel the width of the river TWICE.
Thus, for the second meeting, the distances for M and N each DOUBLE.
We can PLUG IN THE ANSWERS, which represent the width of the river.
The first meeting takes place 750 yards from one of the shores.
When the correct answer choice is plugged in, the second meeting will take place 250 yards from one of the shores.
A: Width = 2000
First meeting:
M=750,
N=1250
M---750---><-------1250-------N
Second meeting:
M=1500,
N=2500
<---750---N M-------1250------->
--------1750---------><---250---
Success!
The second meeting takes place 250 yards from one of the shores.
The correct answer is
A.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3
