I have an amazing bath tub having both hot and cold water taps.
The cold water tap can fill my tub in 6 hours while cold water tap can fill the tub in approx 4 hours.
I turned them on simultaneously but forgot to close the lid which remove water out of tub.
The lid can empty the tub in exact 13 hours.
Since both taps are open along with the lib , can you estimate the time needed to fill the bath tub ?