The Rate of Evaporation of water is the rate at which water evaporates per unit time. It is measured in liters per hour. Following is the how the calculation is done for this question: Volume of water = 4 liters Time taken to evaporate = 20 hours Therefore, Rate of evaporation = Volume of water / Time taken to evaporate = 4 / 20 = 0.2 litres/ hour
