the odds of 2 heads is lower than “at least 1 head”. assuming the outcomes a  is 50%:

the chances of getting 2 heads is 1-in-4, or 25%.

there are 2 more outcomes to get at least 1 head from 2 coin flips: h-t or t-h. the chances of at least 1 head is 3-in-4, or 75%.