2 pipes can separately fill a tank in 20hrs and 30hrs respectively. Both the pipes are opened to fillthe tank, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?  Choose the correct choice from the following answers
A) 10 hrs  B) 12 hrs  C) 16 hrs  D) 18 hrs  E) 20 hrs
1/20 + 1/30 = 1/12   1 + 1/3 = 4/3   1 --- 12   4/3 --- ?     4/3 * 12= 
<gadget id="calculator">  4/3 * 12</gadget>
<output>16</output>
16 hrs   16 hrs
<result>C</result>
2 pipes can separately fill a tank in 20hrs and 30hrs respectively. Both the pipes are opened to fillthe tank, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?