I know that, if X independent events each have a Y chance of happening, the chance of *all* of them happening is just Y to the power of X. So, the odds of flipping a coin 5 times and having them all come up heads is (0.5) to the fifth power, or approximately .032.

But how would you calculate the odds of, for instance, flipping a coin 5 times and having *at least 4* of them come up heads? IOW, the chance of either X or X-n events happening?

TIA.