Question $5.$ Salvage Value and Disposal Cost. $(30$ points total, $15$ points each.$)$

$($a$)$ Assume that unsold seats have salvage value $\backslash ($ s $\backslash )$ after the plane departure $($right after the end of booking or sales horizon$).$ Reformulate the Littlewood formula as well as the EMSRa and EMSRb heuristics taking that value into account.

$($b$)$ Then assume the opposite that any unsold seat incur disposal cost c $($with the convention that $\backslash ($ c$>0\backslash ),$ but still decreasing your revenue$)$ after the plane departure $($right after the end of booking or sales horizon$).$ Reformulate the Littlewood formula as well as the EMSRa and EMSRb heuristics taking that value into account.