A bag contains seven real diamonds and four fake diamonds. If seven diamonds are picked from the bag at random, what is the probability that all seven are real?

Question

Permutations and Combinations Probability Problems

Answer 1

7C7 / 11C7 = 1/330

 

Alternative method: the product of seven ratios: 1/11, 6/10, 5/9, 4/8, 3/7, 2/6, 1/5 which is (also) 1/330.