An elevator started at the first floor and went up 18 floors. it then came down 11 floors and went back up 16. at what floor was it stopped

Started at first floor

went up 18 floors, so now we are at 1+18 or 19th floor

then cam down 11 floors, so now we are at 19-11 or 8th floor

then went up 16, so now at 16+8 or 24th floor

it stopped at 24th floor