if p ( a ) = 8 / 15 , p ( b ) = 4 / 15 , and p ( a â ˆ ª b ) = 16 / 15 find p ( b | a )
"p ( b | a ) = p ( a â ˆ ª b ) / p ( a ) p ( b | a ) = ( 16 / 15 ) / ( 8 / 15 ) = 2 . d"
divide(divide(16, 15), divide(8, 15))