statistics and probability

Question

In a sociology class there are 6 men and 14 women. students are randomly selected to present a topic. What is the probability that at least 1 of the 3 students selected is female? Express your answer as a fraction or a decimal number rounded to four decimal places.

Answer 1

1 - 6/20*5/19*4/18 =

1 - 3/10*5/19*2/9 =

1 - 30/1781 =

(1781 - 30)/1781 =

1751/1781