hygienic hands sac

[batchi94]

we did this experiment where we had to press our finger into agar to see how many bacterial colonies are in the petri dish. we had one dish with unwashed fingers, and one washed with water, hand sanitizer, antibacterial and normal soap. and im guessing as what i wrote for my hypothesis that the unwashed one will grow more bacteria and then water compared to the other ones.

we're not up to the bacteria topic yet but we're already doing the sac so how exactly do we count the number of bacterial colonies? is it clearly seen?
and also, what are the possible limitations in this experiment? can i say that there might still be a small amount of bacteria even our hands were washed? im really confused...
and lastly, what do we have to have in a conclusion to get the highest possible marks?