Tap A can fill a tank in 20 hours and tap B can fill the same tank in 30 hours. If both taps are opened together, then how muchtime will be taken to fill the tank?

10 hours 16 hours 12 hours 24 hours

12 hours

A+ = 20 hrs, B+ = 30 hrs, ⇒ Time required for A + B to fill the tank completely = \(\frac{60}{3+2}\) =  \(\frac{60}{5}\) = 12 hrs.