We extend our two$-$class model to the setting where some of the rejected low$-$fare customers seek to purchase high$-$fare tickets. We have a total capacity C$.$ Let f$1$ and f$2$ be the price of the low$-$fare and high$-$fare tickets. Let the random variables D$1$ and D$2$ capture the low$-$fare and high$-$fare demands. Assume that D$1$ and D$2$ are independent. To model the opportunity to sell high$-$fare tickets to rejected low$-$fare customers, we assume that a fraction $\backslash$alpha in $[0,1]$ of the rejected low$-$fare demand will seek to book high$-$fare tickets. Thus, given a booking limit b$,$ the total high$-$fare demand D$2$ is given by D$2=$ D$2+\backslash$alpha maxD$1$ b$,0.$ Note that the booking limit decision will influence the total high$-$fare demand in the case when low$-$fare demand exceeds the booking limit$.($a$)$ Let EZ$($b$,$ D$1,$ D$2)$ denote the expected total revenue given that the booking limit for low$-$fare customers is set at b$.$ Argue that EZ$($b$,$ D$1,$ D$2)=$ f$1$ E n minb, D$1$ o $+$ f$2$ E n min C $$ minb, D$1,$ D$2+\backslash$alpha maxD$1$ b$,0$