a bag contains 6 black and 3 white balls . one ball is drawn at random . what is the probability that the ball drawn is white ?
"let number of balls = ( 6 + 3 ) = 9 . number of white balls = 3 . p ( drawing a white ball ) = 3 / 9 = 1 / 3 . option b ."
divide(add(divide(divide(factorial(3), factorial(subtract(3, const_2))), factorial(const_2)), divide(divide(factorial(6), factorial(subtract(6, const_2))), factorial(const_2))), divide(divide(factorial(add(6, 3)), factorial(subtract(add(6, 3), const_2))), factorial(const_2)))