Gas pedal on the right?

[ndfan]

I just started my six hours for driving and my instructor told me that the gas pedal is on the right and the brake on the left, when i asked him if the two could be interchanged he just stared at me and began to laugh but gave me no answer. Is the gas pedal always on the right or can it be on either side. Also what do i do in the event a car has a third or fourth pedal.