You and your friend are at a water park, your friend doesn't tell you that he/she can't swim and they began to drown. You pull them out of the water. What should you do next?

Lie them on their back and tilt their chin and head backwards to help clear their airway. This could be enough to get them to start breathing. Check if they’re breathing by leaning over them and placing your cheek near their mouth. look along their chest as you do this to see if their chest is rising and falling, feel for breath on your cheek and listen for breathing sounds. If there is no sign of breath then you should

Give them 5 rescue breaths. Pinch their nose and keep their head tilted back as you breathe into their mouth from yours, making as good a seal as you can with your mouth over theirs. Each breath you give them should last 1 second, and make sure that you take a good deep breath yourself in between each one. These breaths will get valuable oxygen into their lungs, which is particularly important in a drowned casualty. After you’ve done 5 rescue breaths try

CPR. Using both hands together, one on top of the other, push down right in the centre of their chest firmly, with your arms straight. Push down 5-6cm each time, twice a second

How how am i supposed to know