Most people assume the toss of a coin is always a 50/50 probability, with a 50 percent chance it lands on heads, and a 50 percent chance it lands on tails
There is a 50% chance of getting heads, and 50% chance of getting tails.
If these two options are added together, you get 100%. There are only two options on a coin flip anyways, so the probability of getting heads or tails would be 100%.
