(a) What is 'r' in the population equation given below : dN/dt = rN
(b) How does the increase and the decrease in the value of 'r' affect the population size.

Explanation

### Step-by-Step Solution

**(a)** In the population equation given by \( \frac{dN}{dt} = rN \), the variable \( r \) represents the **intrinsic rate of natural increase** of the population. This rate is determined by the difference between the per capita birth rate (B) and the per capita death rate (D) in the population. Mathematically, it can be expressed as:

\[ r = B - D \]

Where:
- \( B \) is the per capita birth rate (the average number of births per individual in a given time period).
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