$($a$)$ Calculate overall gain $\backslash ($ G$\_\{$v$\}\backslash )$ when switch goes to $1.$ Please round to the nearest two decimal places.

$($b$)$ If the switch goes to $2$ the amplitude of the output $\backslash ($ v$\_\{0\}\backslash )$ is halved $($half the original value$),$ in this case what is the value of $\backslash ($ R$\_\{$s$\}\backslash )?$ Please round the nearest whole resistor value.