A river 3 m deep and …

Given, a river 3m deep and 40m wide is flowing at the rate of 2km per hour. Area of cross section of the river = 3 * 40 = 120 m2 Now, volume of water flowing through this cross section in every minute = Area * rate                                                                                                  = 120 * 2 km/hr                                                                                                  = 120 * (2000/60) m/min                                                                                                  = 2 * 2000                                                                                                  = 4000 m3 Since 1 m3 = 1000 litres So, 4000 m3 = 4000 * 1000 litres = 4000000 litres So, in 1 minute, water will fall into the sea is 4000000 litres