Question

In a class of 6, there are 4 students who are secretly robots. If the teacher chooses 2 students, what is the probability that neither of them are secretly robots?

Answer 1

This problem lends itself to the binomial probability approach.

Focus on students who are not secretly robots.

Then P(student is not a robot) = 2/6, or 1/3. Here n=6 and x=2.

Then the desired probability is binompdf(6,1/3, 2), which, by calculator, comes out to 0.329.

Answer 2

2/6 for the first one the first the second is 1/5, so 2/6=1/3, so 1/3 x 1/5 = 1/15 your answer is 1/15