Why does an individual's heart continue beating if brain death is confirmed?

The heart continues to work for a few hours as long as it has oxygen and the ventilator provides enough oxygen to keep the heart beating for several hours.

Can a person feel any pain or suffering after brain death is declared?

No. There is no feeling of pain or suffering as the person is dead.

Can an individual in a coma be already brain-dead?

No. A patient in a coma is not brain-dead as the patient continues to have brain activities and functions.

Does it cost money for me to donate my organ?

There is no cost to the donor family for the donation process. Still, the family's consent is needed to donate organs.