Sunshine Travel Agency specializes in flights between Toronto and Jamaica. It books passengers on Ottawa Air. Sunshine$\text{'}$s fixed costs are $ $25$ comma $500$ per month. Ottawa Air charges passengers $ $1$ comma $400$ per$$ round$-$trip ticket.Calculate the number of tickets Sunshine must sell each month to$($a$)$ break even and$($b$)$ make a target operating income of $ $10$ comma $000$ per month in each of the following independent cases. $($Round up to the nearest whole number. For$$ example, $10\mathrm{.}2$ should be rounded up to$11.)$

$1.$

Sunshine$\text{'}$s variable costs are $ $40$ per ticket. Ottawa Air pays Sunshine $10\%$ commission on ticket price.

$2.$

Sunshine$\text{'}$s variable costs are $ $38$ per ticket. Ottawa Air pays Sunshine $10\%$ commission on ticket price.

$3.$

Sunshine$\text{'}$s variable costs are $ $38$ per ticket. Ottawa Air pays $ $55$ fixed commission per ticket to Sunshine. Comment on the results.

$4.$

Sunshine$\text{'}$s variable costs are $ $38$ per ticket. It receives $ $55$ commission per ticket from Ottawa Air. It charges its customers a delivery fee of $ $8$ per ticket. Comment on the results.