$2\mathrm{.}4$ Your company has a workstation which is equipped with a single$-$core CPU running at frequency of $3$GHz$.$ You are exploring whether r replacing it with a cluster of CPUs is more beneficial. Suppose that $80\%$ of the work running on the workstation is parallelizable.

A$.$ By adding three CPUs$(4$ CPUs in total $).$how much speedup can you get if they all run at the same frequency?$(5\text{'})$

B$.$ If the single$-$core CPU is replaced by a cluster of $100$ CPUs and each of them runs at $1$GHz$.$ How much speedup can you get compared with running with one single$-$core CPU at $3$GHz$?$ If we want to keep the same performance as that of running with one single$-$core CPU at $3$GHz at what frequency would you set each core of the cluster?$(5\text{'})$