We have two implementation of the same instruction set architecture. Machine $$A$$ has a clock cycle time $($clock period$)$ of $1$ ns and CPI of $2\mathrm{.}0$ for some program. Machine $$B$$ has a clock cycle time of $2$ ns and CPI of $1\mathrm{.}2$ for the same. Which machine is faster for this program and by how much? Note: Execution Time $=($#instructions$)($cycles$/$instruction$)($seconds$/$cycle$)$