title: CPI and time of command execution calculation problem
body: <p>A cpu has Clock Cycle equal to 2ns. The execution of arithetics/logical commands demands 4 cycles, execution of branching commands demands 4 cycles and memory access commands 5 cycles. If the frequency of appearance of this types of commands is 40%, 25%, 35% respectively. How much is the average CPI and how much is the average time of command execution? </p>