What is the equation to find your max heart rate?

You can calculate your maximum heart rate by subtracting your age from 220. For instance, if you're 15 years old, subtract 15 from 220 to get a maximum heart rate of 205.

when in a crucial situation, after calling 911, the correct posture for delivering effective compression is the proper hand placement.

first, place two fingers at the sternum, then put the heel of your other hand next to the fingers and place hand on top of the other. lock your elbows by using your body’s weight and compress the victim’s chest with a depth of 2 inches.

moreover, do 15 compression and 2 breaths, this process must be done four times until there is a pulse or a arrive.