How many weeks does it take to empty the lake?

Question

asked Sep 4, 2023 128k views

1 Answer

Melissa Guo · Answer 1 · 2023-09-08T09:19:44+0000

The rate of emptying the lake is -1/8.

The rate of filling the lake is 1/15

Let t be the time in weeks to empty the lake,

Now, add the given rate to get the total rate of emptying of -1/t.

$\begin{gathered} (-1)/(8)+(1)/(15)=-(1)/(t) \\ (-15+8)/(120)=-(1)/(t) \\ -7* t=-120 \\ t=(120)/(7) \end{gathered}$

Thus,

Therefore, it will take 17 weeks and 1 day to empty the lake.