When only the cold water valve is​ opened, a washtub will fill in 5 minutes. When only the hot water valve is​ opened, the washtub will fill in 17 minutes. When the drain of the washtub is​ open, it will drain completely in 6 minutes?

If both the hot and cold water valves are open and the drain is​ open, how long will it take for the washtub to​ fill?