Ata,

First calculate how many moles your 1ml of ethanol represents.

(hint, Avogardro's constant and the molecular mass of ethanol are the starting points)

Secondly, calculate the number of moles in 'air'. Assume a 80:20 ratio of nitrogen to oxygen. Hint, it's the same constant as above, but now your average molecule has a atomic weight (of 0.8*28 + 0.2*32).

This is high school material and can be found in any introductory chemistry text.