claim: Your odds of correctly guessing the outcome of a flipped coin are 1 in 2, but your odds of guessing correctly twice in a row are only 1 in 4 —
evidence: { \displaystyle Y( \omega  )={ egin{ cases }1,&{ 	ext{ if  } }\omega ={ 	ext{ heads } },\[ 6pt ]0,&{ 	ext{ if  } }\omega ={ 	ext{ tails } }.\end{ cases } } } If the coin is a fair coin, Y has a probability mass function f Y { \displaystyle f { Y } } given by : f Y (  y  ) = {  1 2 , if  y = 1 , 1 2 , if  y = 0 , { \displaystyle f { Y }( y )={ egin{ cases }{ 	frac { 1 }{ 2 } },&{ 	ext{ if  } }y=1,\[ 6pt ]{ 	frac { 1 }{ 2 } },&{ 	ext{ if  } }y=0,\end{ cases } } } A random variable can also be used to describe the process of rolling dice and the possible outcomes.