4. Seeing somebody choking can be a very frightening experience and often the first impulse is to try and remove the blockage. This should never be attempted using fingers down the throat, however, as it could cause the throat to swell. The Heimlich manoeuvre can be very effective, but only if you understand how to execute it correctly; if not, it can cause internal damage.
The best bet is to try striking the choking person between the shoulder blades to see if that will dislodge the food.
5. Personally, putting butter on a burn is not something that would spring to my mind if faced with a burnt colleague, but apparently, this is another of those myths that could do more harm than good. Cold water may help to relieve pain and cool the area down, but adding butter to the mix could cause infection and interfere with subsequent treatment.
These questions are in no way intended to gauge whether you should have first aid training or not but could give you an idea of how much you know (or think you know).
The best and safest bet will always be to have appropriate and regular training to ensure that you would know how to act in an emergency.