A tank is empty at first. It takes $$12$$ minutes to fill up the tank completely with Tap $$A$$ alone. It takes $$8$$ minutes to fill up the tank completely with Tap $$B$$ alone. Starting with an empty tank, how long does it take for both taps together to fill half of the tank? 
Overseas Competition->Knowledge Point->Word Problem Modules->Work Word Problems->Pool Filling and Draining Word Problems