$"$If you are long $3$ contracts of $1-$year gold futures with a delivery price $($K$)$ of $$1800,$ what will be your payoff at expiry if the gold price at expiry is $($i$)$ $$1400$

$,($ii$)$ $$1800$

$,($iii$)$ $$2000$

Each contract is $100$ shares. Round to integers."