Urne 1

(R), (N), (R), (N), (N), (R), (R), (R), (R), (R), (R), (R), (R), (R), (R)

Dans une urne, nous avons 3 boules noires (N), et 12 boules rouges (R), indiscernables au toucher.

Quelle est la probabilité de tirer une boule noire (N)?

La probabilité (sous forme de fraction) =


Enter your reply:

 =

This page is not in its usual appearance because WIMS is unable to recognize your web browser.
In order to access WIMS services, you need a browser supporting forms. In order to test the browser you are using, please type the word wims here: and press ``Enter''.

Please take note that WIMS pages are interactively generated; they are not ordinary HTML files. They must be used interactively ONLINE. It is useless for you to gather them through a robot program.