A tap can fill a tank in 6 mins
So the 1st tap's filling rate is
or
and another can fill the same tank in 8 mins .
So the 2nd tap's filling rate is
or
How long will it take to fill the tank if the two taps were opened at the same time?
Let the answer be x mins.
So together they can fill 1 tank in x minutes
So their combined filling rate is
or
Their combined filling rate must be equal to the sum of their
filling rates:








Multiply through by the LCD of 24x











Edwin