A certain program consists of three independent parts A, B and C each of which can execute in parallel on a separate processor. Part A requires 78 billion cycles to complete, part B requires 40 billion cycles to complete and part C requires 62 billion cycles. The program is executed on an SMP system with 4 identical processors all running at the same 2 GHz clock rate.
a) How long does it take to execute the program if three of the processors are disabled and only one is used to execute the program?
b) What is the minimum time required to execute the program if only two of the processors are used to execute the program?
c) What is the minimum time required to execute the program if all processors are used?