From the caselet mentioned presented answer the following questions.

Two tanks, Tank A and Tank B are interconnected to one another through Pipe 1. Pipe 2 and 3 are connected to tank A and fills up the tank within 20 minutes. Pipe 2 Alone takes 30 minutes to fill the tank A. If Pipe 1 is opened after complete filling of Tank A than Tank B gets filled in 15 minutes. If Tank A is half than tank B takes 10 minutes more to fill as valve of pipe 1 gets partially closed due to reducing water pressure. Drain pipe of tank A and B are in parallel connection and hence, can drain both the tanks together in 30 minutes. Tank A can hold two times more water than tank B