There are 3 taps in a keg. If all three are open the keg is drained in one and a half-minute. If tap 1 is closed and the other two are opened the keg drains in 2 minutes. If tap 2 is closed and the others are open it drains in 2 4/13 (two and 4 over 13)minutes. How long will it take to drain the keg if tap 3 is closed and the other two are open?