TS ICET 26 May 2023 Shift 2 Solved Paper

Two pumps A and B can fill a tank respectively in $30\min$. and $60\min$. independently and a drain pipe $\mathrm{C}$ attached at the bottom of the tank can drain a full tank of water in $120\min$. When the tank is empty all the 3 pumps A, B, $\mathit{C}$ are opened at 9.30 am and after few minutes pipe $\mathit{C}$ is closed and $\mathit{A}$ and $\mathit{B}$ are continued. If the tank is filled at $9.51\mathrm{am}$, then the time at which pipe $\mathrm{C}$ is closed is