a bag contains 6 black and 7 white balls . one ball is drawn at random . what is the probability that the ball drawn is white ?
"let number of balls = ( 6 + 7 ) = 13 . number of white balls = 7 . p ( drawing a white ball ) = 7 / 13 hence answer is e"
divide(add(divide(divide(factorial(7), factorial(subtract(7, const_2))), factorial(const_2)), divide(divide(factorial(6), factorial(subtract(6, const_2))), factorial(const_2))), divide(divide(factorial(add(6, 7)), factorial(subtract(add(6, 7), const_2))), factorial(const_2)))