A card is drawn at random from a pack of cards. The probability that the card is either a face card (Jack, Queen, King) or a six is 

A card is drawn at random from a pack of cards

.$n\left(S\right)={ }^{52}{C}_1=52$

A=  event that the card is  a face card (Jack, Queen, King)

B= event that the card is a six

$n\left(A\right)=4\times 3=12$

$n\left(B\right)=4$

$n\left(A\cap B\right)=0$

$P\left(A\cup B\right)=\frac{12+4}{52}=\frac{4}{13}$