MATHEMATICS · Multi-part · CBSE · Mathematics · Permutations and Combinations · Permutations and Combinations
Problem
A box contains 5 white balls and 7 black balls. Four balls are drawn at random from the box without replacement.
(i) How many equally likely ways are there to draw 4 balls from the 12 balls?
(ii) Calculate the probability that none of the balls drawn is white.
(iii) Hence find the probability that at least one of the balls drawn is white.
(iv) Comment on the likelihood of drawing at least one white ball in comparison with drawing none.