Answer the following questions about program P running on processor C:

1. If C has a clock frequency of 2.5 GHz and executes 2 billion instructions each second, what is the average CPI for P?
2. If P is executed in 100 seconds, how many (dynamic) instructions does P have?
3. If 75% of the instructions of P each take one cycle to execute, what is the average CPI for the remaining instructions?
4. When P is executed on processor D (same ISA as C), the average CPI is 20% higher compared to C. If D has a 3.75 GHz clock rate, what is the execution time?
5. What is the speedup of D over C
6. Which one is better: improving the performance of the 90% of the program by 10%, or improving the performance of the 10% of the program by 90%? Calculate the speedup for both and explain.