SOLUTION: A lake is being emptied at a rate that will leave it empty after 16 weeks, while being filled by a river that will fill it in 25 weeks. How long will it take to empty the lake?

Algebra ->  Algebra  -> Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A lake is being emptied at a rate that will leave it empty after 16 weeks, while being filled by a river that will fill it in 25 weeks. How long will it take to empty the lake?      Log On

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Question 622108: A lake is being emptied at a rate that will leave it empty after 16 weeks, while being filled by a river that will fill it in 25 weeks. How long will it take to empty the lake?
Answer by Alan3354(30983) About Me  (Show Source):
You can put this solution on YOUR website!
A lake is being emptied at a rate that will leave it empty after 16 weeks, while being filled by a river that will fill it in 25 weeks. How long will it take to empty the lake?
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Assuming it starts at full:
It loses 1/16 of its volume per week
It gains 1/25 per week
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1/25 - 1/16 = -9/400 of its volume change per week
--> 400/9 weeks