Three coins are tossed,describe two events which are mutually exclusive

Three coins are tossed.
$\therefore$ The sample space =$2^3=8$ possible outcome
$S=\{HHH,HHT,HTH,HTT,THH,THT,TTH,TTT\}$
Let A be the event.'At least two heads show'
$\therefore$ A={HHH,HHT,HTH,THH}
Let B be the event.'At least two tails show'
$\therefore$ B={HTT,THT,TTH,TTT}
$\therefore A \cap B=\phi$
Hence A and B are mutually exclusive events.