Situation $12.$ For the beam shown below, $46.$ Determine the maximum positive moment $($in $kN-m)$ if $x_1=2m.$

A$.30\mathrm{.}0$

C$.27\mathrm{.}5$

B$.25\mathrm{.}0$

D$.20\mathrm{.}0$

$47.$ Find the value of $x_1($in $m)$ causing zero moment at midspan.

A$.2\mathrm{.}5$

C$.2\mathrm{.}75$

B$.2\mathrm{.}0$

D$.2\mathrm{.}25$

$48.$ Calculate the value of $x_1($in $m)$ for the least value of the maximum moment.

A$.2\mathrm{.}93$

C$.2\mathrm{.}07$

B$.2\mathrm{.}50$

D$.1\mathrm{.}38$