Lots of ways. You can use the liquid nitrogen, liquid nitrous oxide (this is what i like to use), topical acids, dermal scraping. You can also try oral cimetadine (400 mg three times a day for 12-16 weeks). This is very safe and had the side effect of getting rid of warts for many people of adult size and weight (japma november 1, 1995 vol. 85 no. 11 717-718 ).
Maybe. Some are and some require multiple treatments.
Several treatments. You can try over the counter wart removers, but be careful: i've seen them do more harm than good. Other options your doctor might offer include cryotherapy (freezing the wart), electrocautery (burning the wart), laser treatment, or several different topical chemical treatments. If the treatment is typically uncomfortable, your doctor can numb the area before proceeding.