The list below shows all of the possible outcomes for flipping four coins.
HHHH
HHHT
HHTH
HHTT
HTHH
HTHT
HTTH
HTTT
THHH
THHT
THTH
THTT
TTHH
TTHT
TTTH
TTTT
What is the probability of at least two coins landing on heads?
StartFraction 5 over 16 EndFraction
StartFraction 3 over 8 EndFraction
One-half
StartFraction 11 over 16 EndFraction
The outcomes where at least two coins land on heads are:
HHHH
HHHT
HHTH
HHTT
HTHH
HTHT
HTTH
THHH
THHT
THTH
TTHH
There are 11 outcomes where at least two coins land on heads out of a total of 16 possible outcomes, so the probability is:
\[ \frac{11}{16} \]