SOLUTION: It took Lance and Ivan 6 hours to travel 33 miles downstream by canoe.The next day the travelled upstream for 8 hours for 20 miles.What was the rate of the current? What was their
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Question 360415: It took Lance and Ivan 6 hours to travel 33 miles downstream by canoe.The next day the travelled upstream for 8 hours for 20 miles.What was the rate of the current? What was their average speed in still water? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! It took Lance and Ivan 6 hours to travel 33 miles downstream by canoe.
The next day the traveled upstream for 8 hours for 20 miles.
What was the rate of the current?
What was their average speed in still water?
:
Let s = their speed in still water
Let c = rate of the current
then
(s+c) = effective speed downstream
and
(s-c) = effective speed upstream
:
Write two distance equations, dist = time * speed
:
6(s+c) = 33
8(s-c) = 20
which is
6s + 6c = 33
8s - 8c = 20
:
Use elimination here, multiply the 1st equation by 8, the 2nd equation by 6
48s + 48c = 264
48s - 48c = 120
-------------------addition eliminates c, find s
96s = 384
s =
s = 4 mph in still water
:
Find s: using: 6s + 6c = 33
6(4) + 6c = 33
6c = 33 - 24
6c = 9
c =
c = 1.5 mph is the current
:
:
Check these solutions in the 2nd equation 8(s-c) = 20
8(4 - 1.5) =
8 * 2.5 = 20; confirms our solutions
