A leaf of `20cm^(2)` growth `5cm^(2)` per hour and B leaf of `25cm^(2)` grows `5cm^(2)` per hour
The relative growth rate of leaf A and B respectively is

Options

A. 25% and 20%
B. 20% and 25%
C. 50% and 100%
D. 25% and 50%

Answer

To find the relative growth rate (RGR) of leaf A and leaf B, we can follow these steps:

### Step 1: Understand the Definitions
- **Absolute Growth (AG)**: The actual increase in size of the leaf, measured in cm².
- **Relative Growth Rate (RGR)**: The growth rate relative to the initial size of the leaf, expressed as a percentage.

### Step 2: Calculate the Relative Growth Rate for Leaf A
1. **Identify the initial size and absolute growth for Leaf A**:
- Initial size (A_initial) = 20 cm²
- Absolute growth (A_AG) = 5 cm² per hour

2. **Use the formula for RGR**:
\[ RGR_A = \left( \frac{A_{AG}}{A_{initial}} \right) \times 100 \]
\[ RGR_A = \left( \frac{5}{20} \right) \times 100 \]
\[ RGR_A = 0.25 \times 100 = 25\% \]

### Step 3: Calculate the Relative Growth Rate for Leaf B
1. **Identify the initial size and absolute growth for Leaf B**:
- Initial size (B_initial) = 25 cm²
- Absolute growth (B_AG) = 5 cm² per hour

2. **Use the formula for RGR**:
\[ RGR_B = \left( \frac{B_{AG}}{B_{initial}} \right) \times 100 \]
\[ RGR_B = \left( \frac{5}{25} \right) \times 100 \]
\[ RGR_B = 0.20 \times 100 = 20\% \]

### Step 4: Present the Final Results
- The relative growth rate of Leaf A is **25%**.
- The relative growth rate of Leaf B is **20%**.

### Final Answer:
The relative growth rates of leaf A and leaf B are 25% and 20%, respectively.

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