In a pond there are 20 lotus plants last year and through reproduction 8 new plants are added, taking the current population to 28. What is the birth rate?

Options

A. `0.1`
B. `0.4`
C. `0.28`
D. `0.5`

Answer

To calculate the birth rate of the lotus plants in the pond, we can follow these steps:

### Step 1: Identify the initial population
The initial population of lotus plants last year was 20.

### Step 2: Identify the number of new plants added
Through reproduction, 8 new lotus plants were added.

### Step 3: Calculate the change in population
The change in population can be calculated by subtracting the initial population from the current population:
\[ \text{Change in Population} = \text{Current Population} - \text{Initial Population} = 28 - 20 = 8 \]

### Step 4: Calculate the birth rate
The birth rate is defined as the change in population divided by the original population. Therefore:
\[ \text{Birth Rate} = \frac{\text{Change in Population}}{\text{Initial Population}} = \frac{8}{20} \]

### Step 5: Simplify the fraction
To simplify \(\frac{8}{20}\):
\[ \frac{8}{20} = 0.4 \]

### Conclusion
Thus, the birth rate of the lotus plants in the pond is 0.4.

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