81 Sur un axe gradué, on donne les points
Al+ 7) et B(- 9).
a. Quelle peut être l'abscisse de C, sachant que
AC = 11?
b. Quelle peut être l'abscisse de D, sachant que
BD = 4 et que D est entre A et B?

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?