Problem $6-(20$ Points$)$: $(5$ pts each$)$

students were taught how to determine equivalent small$-$signal impedance and voltage gain of given amplifier by inspection. Determine the small$-$signal voltage gain, $\backslash ($ v$\_\{\backslash$text $\{$out $\}\}/$ v$\_\{$i n$\}\backslash ),$ for the schematics shown below. You do not have to use small$-$signal equivalent circuits. You may directly write down the answers by inspection. If you are able to do this, you can save lots of time in determining first order calculation. Assume appropriate bias voltage Vb is applied to ensure all transistors are in saturation.

$($b$)$