if a card is drawn from a well shuffled deck of cards , what is the probability of drawing a black card or a face card ?
"p ( b á ´ œ f ) = p ( b ) + p ( f ) - p ( b â ˆ © f ) , where b denotes black cards and f denotes face cards . p ( b á ´ œ f ) = 26 / 52 + 12 / 52 - 6 / 52 = 8 / 13 answer : d"
add(divide(const_3, const_52), divide(divide(const_52, const_4), const_52))