Let R's salary be 100.

• Since Q’s salary is 20% lower than R’s, Q’s salary = $100 - 20 = 80$.
• P’s salary is 20% lower than Q’s, so P’s salary = $80 - (20\% \text{ of } 80) = 80 - 16 = 64$.

Now, to find how much R’s salary is more than P’s:

• Difference = $100 - 64 = 36$.
• Percentage difference = $(\frac{36}{64}) \times 100 = 56.25\%$.

Answer: B. 56.25%