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?

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(69443) (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?
------------
Assuming it starts at full:
It loses 1/16 of its volume per week
It gains 1/25 per week
--------
1/25 - 1/16 = -9/400 of its volume change per week
--> 400/9 weeks

RELATED QUESTIONS
Officials begin to release water from a full man-made lake at a rate that would empty the (answered by ikleyn,Theo)

Officials begin to release water from a full man-made lake at a rate that would empty the (answered by stanbon)

officials begin to release water from a full man made lake at a rate that would empty the (answered by ikleyn)

Officials begin to release water from a full man-made lake at a rate that would empty the (answered by josmiceli)

Officials begin to release water from a full man-made lake at a rate that would empty the (answered by math_tutor2020,greenestamps)

Officials begin to release water from a full man-made lake at a rate that would empty the (answered by josgarithmetic,macston)

Officials begin to release water from a full man-made lake at a rate that would empty the (answered by solver91311)

Officials begin to release water from a full man-made lake at a rate that would empty the (answered by stanbon)

officials begin to release water from a full man made lake at a rate that would empty the (answered by ankor@dixie-net.com)