Answer:
T(n)=n(n+1)/2
Explanation:
See the attached picture for detailed explanation.
Answer:
Achieved Instruction per cycle rate is 
Solution:
As per the question:
Execution time, t = 1.4 s
No. of instructions being executed, n = 1.8 billion =
Clock speed of CPU, f = 3.2 GHz = 
Now, to calculate the actual issue rate achieved:
CPI (Cycle per Instruction) = 
CPI = 
Instruction per cycle is given as the reciprocal of CPI:
Instruction per cycle = 
Google c++ tutorial. Cplusplus and Tutorials Point both have some good resources