Let \( M \) and \( A \) represent the speeds of Mira and Amal in rounds per minute, respectively.
\[ (A - M) \times 45 = 3 \Rightarrow A - M = \frac{1}{15} \]
\[ (A + M) \times 3 = 1 \Rightarrow A + M = \frac{1}{3} \]
Solving the system of equations formed by the two conditions:
\[ A - M = \frac{1}{15} \quad \text{(1)} \\ \] \[ A + M = \frac{1}{3} \quad \text{(2)} \]
Adding equation (1) and equation (2):
\[ 2A = \frac{1}{15} + \frac{1}{3} = \frac{1 + 5}{15} = \frac{6}{15} = \frac{2}{5} \Rightarrow A = \frac{1}{5} \]
Substituting the value of \( A \) back into equation (2):
\[ \frac{1}{5} + M = \frac{1}{3} \Rightarrow M = \frac{1}{3} - \frac{1}{5} = \frac{5 - 3}{15} = \frac{2}{15} \]
Therefore, Mira's speed is \( \frac{2}{15} \) rounds per minute.
In one hour (60 minutes), Mira completes: \[ 60 \times \frac{2}{15} = 8 \text{ rounds} \]
Answer: 8 rounds