Answer:
instruction executed = cycles executed / CPI = 45 x 109 / 2 = 22.5 x 109 
Modification: 
reduce execution time by 20 % 
CPI increased by 25%
Step-by-step explanation:
What is number of instructions executed by this processor during the program? 
Answer: 
instruction executed = cycles executed / CPI = 45 x 109 / 2 = 22.5 x 109 
Modification: 
reduce execution time by 20 % 
CPI increased by 25%