Question

Probability Q !

Answer 1

In a race are 10 competitors:A,B,...,J
a).3 Competitors are choosen.What is the probability p1 that these competitors to be placed at the end of the race on the first 3 places in the same order with the election one's;
b).What is the probability p2 that this 3 competitors choosen to ocuppy the first 3 places without taking count of order.
c).4 Competitors are choosen.What is the probability p3 that among those 4 competitors to be 3 winners(1st,2nd,3rd)?.

Answer 2

for p1 my guess is this: