(a) 18C4
(b) 18C4 - 12C4
A sample of 4 balls is to be selected at random from an urn containing 18 balls numbered 1 to 18. Five balls are green, 6 balls are white, and 7 balls are black.
(a) How many different samples can be selected?
samples
(b) How many samples can be selected that contain at least 1 white ball?
samples
1 answer
1 answer