Question I. $(10$ points$)$ Let Array $A[1$:$70]=11,12,$dots.,$79,80.$ How many element comparisons are

performed by Algorithm BINARYSEARCH when searching for the following values of $x?$ You need to show

how you get your final answer.

$($a$)20$

$($b$)45\mathrm{.}5$

$($c$)81$