$1\mathrm{.}16$ A program includes $80\%$ multiplications $(5$ cycles$)$ and $20\%$ additions $(1$ cycle$).$ Suppose multiplications can be improved by $5$ folds, can we get $5-$fold overall improvement? Why? $(3$ points$)$

$1\mathrm{.}17$ Briefly explain Fetch$-$Execute cycle. $(3$ points$)$

$-$Fetch$-$Execute cycle is