1. Suppose that there are five PCs in the network and all five PC users are active only 10

percent of the time and is idle during the remaining 90 percent of the time. Also, suppose

that all PCs are powered on and connected to the Internet for 24 hours. Calculate how long

there are no available PCs resources for 24 hours. [2 points]

2. Consider a $3000 wafer having 30 cm diameter. This wafer will be chopped into dies that

are 0.7 cm on a side. [3 points]

a) How many dies can we produce?

b) If we assume a yield is 0.6, how many good dies can we produce?

c) How much does each die cost?

3. Consider the following set of processes, with the length of the CPU execution time given

in milliseconds. The processes are assumed to have arrived in the order P1, P2, P3, P4, at

the following times. [3 points]

Process Arrival Time Execution Time

---------------------------------------------------------------------------------

P1 0 6

P2 1 3

P3 3 4

P4 4 1

(a) Draw CPU grant chart that illustrates the execution of these processes using the FcFS,

SJF with non-preemptive, and SJF with preemptive scheduling, respectively.

(b) Calculate the average waiting time over all processes for FcFS, SJF with non-

preemptive, and SJF with preemptive.

4. Assume that we are going to replace the CPU in a computer with a faster version. This new

CPU is known providing 10 times faster on a computation in the floating point calculations

than the original CPU. The original CPU is currently busy with floating point calculations

50% of time and doing other calculations remaining 50 % of time. What is the overall

speedup gained by incorporating enhancement? [2 points]