The concentration of dissolved Oxygen in water for growth of fish should be more than X ¯ ppm and Biochemical Oxygen Demand in clean water should be less than Y ¯ ppm . X and Y in ppm are, respectively.

Step-by-step solution

The concentration of dissolved oxygen in water is very important for aquatic life. If the concentration of dissolved oxygen of water is below 6 ppm, the growth of fish gets inhibited. The amount of oxygen required by bacteria to break down the organic matter present in a certain volume of a sample of water, is called Biochemical Oxygen Demand (BOD). The amount of BOD in the water is a measure of the amount of organic material in the water, in terms of how much oxygen will be required to break it down biologically.