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Question 137774: Okay, I have another one using distance = rate times time but it has a twist. I am totally stuck! Please help!
A penguin swimming with the ocean current in search of food takes 1 hour to travel 9 miles. Its return trip upstream to its starting point takes it 3 hours. What is the penguin's speed in still water?
I figured its speed with the current and against it but have no idea how to figure out still water. HELP!
with current- 9=1r so r=9
against current- 9=3r so r=3
Now what???
Answer by Fombitz(32388)   (Show Source):
You can put this solution on YOUR website! No, you need to figure in the ocean current in the rate.
Let's call the it R.
If the penguin floats (doesn't swim), then he would travel at rate, R.
When he's with the current, his rate is P+R, where P is his speed in still water.
When he's against the current, his rate is P-R.
Remember rate times time equals distance.
The distance is 9 miles.
Time with current is 1 hours.
Time against current is 3 hours.
1.
2.
Simplifying
1.
2.
The simplest way is to add the two together to cancel out R.
From 1,
The ocean current, R, is 3 miles per hour.
The penguin speed, P, in still water is 6 miles per hour.
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