Question 777946
The rate of filling is:
( 1 tank ) / ( 9 hrs )
Let {{{ -R }}} = the rate that the leak empties the tank
------------------
Starting with an empty tank, add the rates to get
the total rate needed to fill the tank
{{{ 1/9 - R = 1/10 }}}
------------------
{{{ R = 1/9 - 1/10 }}}
{{{ R = 10/90 - 9/90 }}}
{{{ R = 1/90 }}}
The rate of leaking is ( 1 tank ) / ( 90 hrs )
------------------------------------
So, if the tank is full, the tank will empty in 90 hrs