Problem $4(1$ pt$)$ An airline is operating the two$-$flight network as below:

The capacities of these flights are as follows:

$-$ Istanbul$-$Doha:$220-$seat

$-$ Doha$-$Perth: $320-$seat

Assume that we know the future demand for every ODF with certainty. Demands and fares are as follows:

a$)(0\mathrm{.}6$ pts $)$ What are the unconstrained demand for these two flights? Note that unconstrained demand is the total number of customers for a particular flight that the manger could sell if accepting every booking request is possible $($thus it can be well above the capacity$).$

b$)(0\mathrm{.}4$ pts $)$ Determine whether or not the greedy heuristic will fail for this problem and explain why.