6 in every 10000 students score perfect on sat score. A random sample of 3 students who took sat is taken.?

Question

Let x equal the # of them who score perfect on sat.
What is p(x) for x =0,1,2,3?

Answer 1

P(perfect SAT) = 6/10000 = 3/5000
P(not perfect SAT) = 1 - P(perfect SAT) = 9994/10000 = 4997/5000

The following are really close to the correct answers given you have a large population:
P(0) = (4997/5000)^3
P(1) = C(3,1) * (4997/5000)² * (3/5000)
P(2) = C(3,1) * (4997/5000) * (3/5000)²
P(3) = (3/5000)^3