Simple Explanation
Area constant होने पर density population के directly proportional होती है। Population 20 percent कम होने पर \(Population/Area\) ratio भी exactly 20 percent कम होगा। इसलिए पहला विकल्प सही है। Area unchanged होने से कोई compensating effect नहीं है। परीक्षा में constant-area questions में population के proportional change को density के same proportional change से जोड़ें। / When area remains constant, density is directly proportional to population. A 20 percent decrease in population produces exactly a 20 percent decrease in the \(Population/Area\) ratio. Therefore, the first option is correct. There is no compensating effect because area does not change. In examinations, with constant area, apply the same proportional change in population to density.
