SOLUTION: #2 A CRUISE BOAT TRAVELS 96 MILES DOWNSTREAM IN 4 HOURS AND RETURNS TO ITS STARTING POINT UPSTREAM IN 12 HOURS. FIND THE SPEED OF THE STREAM.

Algebra.Com
Question 234233: #2 A CRUISE BOAT TRAVELS 96 MILES DOWNSTREAM IN 4 HOURS AND RETURNS TO ITS STARTING POINT UPSTREAM IN 12 HOURS. FIND THE SPEED OF THE STREAM.

Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
A CRUISE BOAT TRAVELS 96 MILES DOWNSTREAM IN 4 HOURS AND RETURNS TO ITS STARTING POINT UPSTREAM IN 12 HOURS. FIND THE SPEED OF THE STREAM.
:
Let s = speed of the boat in still water
Let c = speed of the stream
then
(s+c) = speed downstream
(s-c) = speed upstream
:
Write a distance equation for each trip; dist = time * speed
:
4(s +c) = 96
12(s-c) = 96
:
Simplify, divide the 1st equation by 4 and the 2nd equation by 12
s + c = 24
s - c = 8
-------------subtraction eliminates s, find c:
2c = 16
c = 8 mph, speed of the stream, (which is what they asked for)
:
:
To check solution find the speed of the boat
s - 8 = 8
s = 16 mph, speed of the boat
:
Check in both equations
4(16+8) = 96
12(16-8) = 96

RELATED QUESTIONS

a cruise boat travels 96 miles downstream in 2 hours and returns to its starting point... (answered by checkley77)
A cruise boat travels 36 miles downstream in 4 hours and returns to its starting point... (answered by FrankM)
A cruise boat travels 96 miles downstream for 2 hours and returns to its starting point... (answered by stanbon)
A cruise boat travels 60 miles downstream in 3 hours and returns to its starting point... (answered by orca)
a cruise boat travels 24 miles downstream in 3 hours and returns to its starting point... (answered by stanbon,checkley71)
#1: The speed of a stream is 6mph If a boat travels 54 miles downstream in the same... (answered by ewatrrr)
A cruise boat travels 48 miles downriver in 4 hours and returns to its starting point... (answered by Alan3354)
a cruise boat travels 24 miles downstreamin 3 hoursand returns to its starting point... (answered by checkley71)
A cruise boat travels 12 miles downstream in 3 hours and returns upstream in 6 hours.... (answered by jim_thompson5910)