What is the probability of at least one head?

If you throw a single fair coin multiple times, the probability of getting NO head is:For 1 throw: 1/2

For 2 throws: 1/2 squared = 1/4

For 3 throws: 1/2 cubed = 1/8

etc.

The probability of getting AT LEAST ONE head is the complement; for example, for 3 throws, it would be 1 minus 1/8.