# Three coins are tossed,describe two events which are mutually exclusive but not exhaustive.

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 "Exactly one head"
$A=\{HTT,THT,TTH\}$
Let B be the event "Exactly two heads"
$B=\{HHT,HTH,THH\}$
$\therefore A \cap B \neq \phi$ and $A\cup B\neq S$
$\therefore$ A and B are mutually exclusive but not exhaustive.