Question 1164125
.
<pre>

You may check it on your own, that the rate of draining is  7500 liters per hour.


Having this info, you can easily calculate the necessary time by dividing the total volume of 80000 L by 7500 L.


<U>ANSWER</U>.  The pool will be empty in 10 {{{2/3}}} hours = 10 hours and 40 minutes after the starting moment.
</pre>