A boat covers 143 km upstream in 13 hours and the same distance downstream in 11 hours. What is the speed (in km / hr ) of the boat in still (without stream) water?
A boat covers 143 km upstream in 13 hours and the same distance downstream in 11 hours. What is the speed (in km / hr ) of the boat in still (without stream) water? সঠিক উত্তর 12 km/hr