if p ( a ) = 2 / 15 , p ( b ) = 4 / 15 , and p ( a â ˆ ª b ) = 6 / 15 find p ( b | a )
p ( b | a ) = p ( a â ˆ ª b ) / p ( a ) p ( b | a ) = ( 6 / 15 ) / ( 2 / 15 ) = 3 . c
divide(divide(6, 15), divide(2, 15))