SOLUTION: a boat has a speed of 15 mph in still water. It travels downstream from Greentown, in three-fifths of an hour. It then goes back upstream from Glenavon to Cambria, which is two mil

Question 103901: a boat has a speed of 15 mph in still water. It travels downstream from Greentown, in three-fifths of an hour. It then goes back upstream from Glenavon to Cambria, which is two miles downstream from Greentown, in three fithts of an hour. Find the rate of the current.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
a boat has a speed of 15 mph in still water. It travels downstream from Greentown, in three-fifths of an hour. It then goes back upstream from Glenavon to Cambria, which is two miles downstream from Greentown, in three fithts of an hour. Find the rate of the current.
-----------
Let rate of the current be "c".
------------
Downstream DATA:
Time = (3/5) hr ; distance = x miles ; Rate = x/(3/5)= 5x/3 mph
------------
Upstream DATA:
Time = (3/5)hr ; distance= x-2 miles ; Rate = (x-2)/(3/5) = 5(x-2)/3 mph
-----------------
EQUATIONS:
Rate downstream: 15+c = 5x/3
Rate upstream : 15-c = 5(x-2)/3
---------------
Add to get: 30 = [5x/3] + [5(x-2)/3]
Multiply thru by 3 to get:
5x + 5(x-2) = 90
10x=100
x = 10 miles
----------------
Substitute into 15+c = 5x/3 to solve for "c":
15+c = 50/3
c = 50/3 - 45/3 = 5/3 mph
-----------------
Rate of the current is (5/3) mph
===================
Cheers,
Stan H.
RELATED QUESTIONS
A boat has a speed of 15 mph in still water. It travels downstream from Greentown to... (answered by ikleyn)

A boat on a river travels the same distance in 1/2 hour downstream as it can go upstream... (answered by ankor@dixie-net.com)

A boat, whose speed in still water is 8Km per hour travels 12Km upstream and then 16Km... (answered by jorel1380)

A boat, whose speed in still water is 8Km per hour travels 12Km upstream and then 16Km... (answered by emargo19)

A boat goes 15 miles per hour in still water. If it can go 12 miles downstream in the... (answered by stanbon)

the speed of a stream is 5 mph. a boat travels 1 mile per hour in the time it takes to... (answered by stanbon)

a paddle boat travels 9 miles upstream (against the current) in the same time it travels (answered by jorel555)

The speed of a stream is 4 mph. A boat travels 7 miles upstream in the same time it... (answered by drk,stanbon,checkley77)

Suppose a boat has a speed in still water of 10 mph. The boat travels 48 miles upstream... (answered by kevwill)